Agilent U1251B and U1252B Handheld Digital Multimeter User’s and Service Guide Agilent Technologies
Notices © Agilent Technologies, Inc. 2009 Warranty No part of this manual may be reproduced in any form or by any means (including electronic storage and retrieval or translation into a foreign language) without prior agreement and written consent from Agilent Technologies, Inc. as governed by United States and international copyright laws. The material contained in this document is provided “as is,” and is subject to being changed, without notice, in future editions.
Safety Symbols The following symbols on the instrument and in the documentation indicate precautions which must be taken to maintain safe operation of the instrument.
Safety Information This meter is safety-certified in compliance with EN/IEC 61010-1:2001, UL 61010-1 Second Edition and CAN/CSA 22.2 61010-1 Second Edition, CAT III 1000 V/ CAT IV 600 V Overvoltage Protection, Pollution Degree II. Use with standard or compatible test probes. General Safety Information The following general safety precautions must be observed during all phases of operation, service, and repair of this instrument.
WARN IN G • When working above 70V DC, 33 V AC RMS or 46.7 V peak, exercise caution – such range pose a shock hazard. • Do not measure more than the rated voltage (as marked on the meter) between terminals, or between terminal and earth ground. • Double-check the meter’s operation by measuring a known voltage. • For current measurement, turn off circuit power before connecting the meter to the circuit. Always place the meter in series with the circuit.
CAU T ION VI • Turn off circuit power and discharge all high-voltage capacitors in the circuit before you perform resistance, continuity, diodes, or capacitance tests. • Use the correct terminals, function, and range for your measurements. • Never measure voltage when current measurement is selected. • Use only recommended rechargeable battery. Ensure proper insertion of battery in the meter, and follow the correct polarity. • Disconnect test leads from all the terminals during battery charging.
Regulatory Markings The CE mark is a registered trademark of the European Community. This CE mark shows that the product complies with all the relevant European Legal Directives. The C-tick mark is a registered trademark of the Spectrum Management Agency of Australia. This signifies compliance with the Australia EMC Framework regulations under the terms of the Radio Communication Act of 1992. ICES/NMB-001 indicates that this ISM device complies with the Canadian ICES-001.
Waste Electrical and Electronic Equipment (WEEE) Directive 2002/96/EC This instrument complies with the WEEE Directive (2002/96/EC) marking requirement. This affixed product label indicates that you must not discard this electrical/electronic product in domestic household waste. Product Category: With reference to the equipment types in the WEEE directive Annex 1, this instrument is classified as a “Monitoring and Control Instrument” product. The affixed product label is as shown below.
Declaration of Conformity (DoC) The Declaration of Conformity (DoC) for this instrument is available on the Web site. You can search the DoC by its product model or description. http://regulations.corporate.agilent.com/DoC/search.htm N O TE If you are unable to search for the respective DoC, please contact your local Agilent representative.
X Agilent U1251B/U1252B User’s and Service Guide
Contents 1 Getting Started Tutorial 1 Introducing the Agilent U1251B and U1252B Handheld Digital Multimeter 2 Adjusting the Tilt-Stand 3 The Front Panel at a Glance 5 The Rotary Switch at a Glance 6 The Keypad at a Glance 7 The Display at a Glance 9 Selection of Display by Hz Button 13 Selection of Display by Dual Button 15 Selection of Display by Shift Button 18 The Terminals at a Glance 20 The Rear Panel at a Glance 21 2 Making Measurements 23 Measuring Voltage 24 Measuring Current 27 Measuring DC volt
Contents XII 3 Features and Functions 45 Dynamic Recording 46 Data Hold (Trigger Hold) 48 Refresh Hold 49 Null (Relative) 51 Decibel Display 53 1 ms Peak Hold 55 Data Logging 57 Manual Logging 57 Interval Logging 59 Reviewing Logged Data 61 Square Wave Output (for U1252B) 63 Remote Communication 67 4 Changing The Default Setting 69 Selecting Setup Mode 70 Setting Data Logging Mode 74 Setting Thermocouple Types (for U1252B) 75 Setting Reference Impedance for dBm Measurement 76 Setting Minimum Frequency
Contents Replacing the Fuse 103 Troubleshooting 105 6 Performance Tests and Calibration 107 Calibration Overview 108 Closed-case Electronic Calibration 108 Agilent Technologies Calibration Services 108 Calibration Interval 108 Adjustment is Recommended 109 Recommended Test Equipment 110 Basic Operating Test 111 Backlit Test 111 Testing the Display 111 Current Terminal Test 112 Charge Terminal Alert Test 113 Test Considerations 114 Input Connections 115 Performance Verification Tests 116 Calibration Securi
Contents Operating Specifications 152 General Specifications 154 XIV Agilent U1251B/U1252B User’s and Service Guide
Agilent U1251B and U1252B Handheld Digital Multimeter User’s and Service Guide 1 Getting Started Tutorial Introducing the Agilent U1251B and U1252B Handheld Digital Multimeter 2 Adjusting the Tilt-Stand 3 The Front Panel at a Glance 5 The Rotary Switch at a Glance 6 The Keypad at a Glance 7 The Display at a Glance 9 Selection of Display by Hz Button 13 Selection of Display by Dual Button 15 Selection of Display by Shift Button 18 The Terminals at a Glance 20 The Rear Panel at a Glance 21 This chapter cont
1 Getting Started Tutorial Introducing the Agilent U1251B and U1252B Handheld Digital Multimeter The handheld digital multimeter’s key features are: • DC, AC and AC + DC (only U1252B) voltage and current measurements.
Getting Started Tutorial 1 • 50,000 count precision true RMS digital multimeter, designed to meet IEC61326- 1:2005 / EN61326- 1:2006 Category III 1000 V/ CAT IV 600 V Overvoltage Protection, Pollution Degree II standards Adjusting the Tilt-Stand To adjust the meter to a 60° standing position, pull the tilt- stand outwards to its maximum reach.
Getting Started Tutorial 1 To adjust the meter to a hanging position, flip the stand upwards and over its maximum reach until it is detached from its hinge. Then flip the stand over so that the stand’s inner surface is facing the meter’s rear. Now, press the stand down into its hinge. Follow the step by step pictorial instructions below.
Getting Started Tutorial 1 The Front Panel at a Glance Display Keypad Rotary switch Terminals Agilent U1251B/U1252B User’s and Service Guide 5
1 Getting Started Tutorial The Rotary Switch at a Glance 5 4 3 6 7 8 2 9 1 10 Legend: 6 No.
Getting Started Tutorial 1 The Keypad at a Glance The operation of each key is shown below. Pressing a key illuminates a related symbol on the display and sounds the beeper. Turning the rotary switch to another position resets the current operation of the key. Figure below shows the keypad of the U1252B. The ms% (Pulse width/Duty cycle), Hz , and frequency counter functions are only available on the U1252B.
1 Getting Started Tutorial Function when pressed for less than 1 second Function when pressed for more than 1 second 4 scrolls through the measuring function(s) at a particular rotary switch position. enters Log Review mode. Press to switch to manual or interval logging data. Press or to view first or last logged data respectively. Press or to scroll up or down logged data. Press for more than 1 second to exit mode.
Getting Started Tutorial 1 The Display at a Glance To view the full display (with all segments illuminated), press and hold button while turning the rotary switch from OFF to any non- OFF position. After you are done viewing the full display, press any button to resume normal functionality based on the rotary switch position. This is followed by a wake- up feature. The meter will then enter power save mode once auto power off (APF) is enabled.
1 Getting Started Tutorial LCD Sign Description Remote control Thermocouple types: NULL (K-type) (J-type) Null math function Diode / Audible continuity Audible continuity for resistance View mode for checking logged data Data logging indication Square wave output (only U1252B) • Positive slope for pulse width (ms) and duty cycle (%) measurement • Charging capacitor as capacitance measurement • Negative slope for pulse width (ms) and duty cycle (%) measurement • Discharging capacitor as capaci
Getting Started Tutorial 1 The primary display signs are described below.
1 Getting Started Tutorial The secondary display signs are described below.
Getting Started Tutorial 1 The “+” or “–” sign is indicated when the positive or negative value has been measured or calculated. Each segment represents 2500 or 500 counts depending on the range indicated on the peak bar graph. See the table below.
1 Getting Started Tutorial primary display by pressing again. This enbles the simultaneous monitoring of real- time voltage and current with frequency, duty cycle or pulse width. Voltage or current resumes on primary display after you press and hold for more than 1 second.
Getting Started Tutorial Frequency (Hz) 1 AC + DC µA Pulse width (ms) (AC + DC current) [for U1252B] Duty cycle (%) Frequency (Hz) AC mA or A Pulse width (ms) (AC current) Duty cycle (%) Frequency (Hz) DC mA or A Pulse width (ms) (DC current) Duty cycle (%) Frequency (Hz) (AC + DC current) [for U1252B] Pulse width (ms) Hz (Frequency counter) - press Frequency (Hz) AC + DC mA Duty cycle (%) -1- Pulse width (ms) to select frequency division by 1 [for U1252B] Duty cycle (%) Hz (Frequency
1 Getting Started Tutorial Rotary switch position Primary display Secondary display AC V Hz (AC coupling) dBm or dBV (select AC V (Function) (AC voltage) by pressing for U1252B (AC voltage) for U1251B/ for U1252B (DC voltage) for U1252B (AC + DC voltage) (AC voltage) (DC voltage) N O TE 16 ) AC V Ambient temperature °C or °F AC V Hz (AC coupling) dBm or dBV (1) AC V AC V DC V AC V Ambient temperature °C or °F DC V dBm or dBV Hz (DC coupling) (1) DC V DC V AC V [for U1252B] DC
Getting Started Tutorial (AC + DC voltage) [for U1252B] AC + DC mV Hz (AC coupling) dBm or dBV AC + DC mV AC + DC mV AC mV AC + DC mV DC mV AC + DC mV Ambient temperature °C or °F DC μA Hz (DC coupling) DC μA AC μA DC μA Ambient temperature °C or °F AC μA Hz (AC coupling) AC μA DC μA AC μA Ambient temperature °C or °F AC + DC μA Hz (AC coupling) (AC + DC current) AC + DC μA AC μA [for U1252B] AC + DC μA DC μA AC + DC μA Ambient temperature °C or °F DC mA Hz (DC coupling)
1 Getting Started Tutorial (AC current) (AC + DC current) [for U1252B] (Capacitance) (Diode)/ Ω (Resistance)/ nS (Conductance) (Temperature) AC A Hz (AC coupling) AC A DC A AC A Ambient temperature °C or °F AC + DC A Hz (AC coupling) AC + DC A AC A AC + DC A DC A AC + DC A Ambient temperature °C or °F nF / V / Ω / nS Ambient temperature °C or °F °C (°F) Ambient temperature °C or °F °C (°F) Ambient temperature °C or °F / 0°C compensation (select by pressing ) Selection of Display by
Getting Started Tutorial for U1252B (AC + DC Voltage) 1 DC mV AC mV AC + DC mV Ω Ω Ω nS Diode Hz Capacitance Temperature / DC μA AC μA Square wave output for AC + DC μA [for U1252B] DC mA AC mA AC + DC mA %(0–20 or 4–20) DC A AC A AC + DC A [for U1252B] Duty cycle (%) Pulse width (ms) U1252B N O TE 1. Press Press only. Agilent U1251B/U1252B User’s and Service Guide to switch between dBm and dBV measurement.
1 Getting Started Tutorial The Terminals at a Glance To avoid damaging this device, do not exceed the input limit. WARN IN G Figure 1-1 U1252B Connector terminals Table 1-2 Terminal connections for different measuring functions Rotary switch position Input terminal Overload protection COM 1000 V R.M.S., for U1252B for U1251B 1000 V R.M.S. for short circuit <0.3 A Ω for U1252B μA .
Getting Started Tutorial 1 The Rear Panel at a Glance IR communication port Test probe holders Battery access cover Figure 1-2 Agilent U1251B/U1252B User’s and Service Guide Rear panel of U1252B 21
1 22 Getting Started Tutorial Agilent U1251B/U1252B User’s and Service Guide
Agilent U1251B and U1252B Handheld Digital Multimeter User’s and Service Guide 2 Making Measurements Measuring Voltage 24 Measuring AC voltage 24 Measuring DC voltage 26 Measuring Current 27 μA & mA Measurement 39 % Scale of 4–20 mA 28 A measurement 29 Frequency Counter 30 Measuring Resistance, Conductance and Testing Continuity 32 Testing Diodes 36 Measuring Temperature 40 Alerts and Warning During Measurement 43 Overload Alert 43 Input Warning 43 Charge Terminal Alert 44 This chapter contains detailed i
2 Making Measurements Measuring Voltage The meter offers true- RMS readings for AC measurements that are accurate for sine waves, square waves, triangle waves, staircase waves and other waveforms without any DC offset. For AC with DC offset, use AC + DC measurement on or rotary switch location. This applies only to U1252B. WARN IN G Ensure that the terminal connections are correct for that particular measurement before proceeding with the measurement.
Making Measurements 2 Figure 2-1 Agilent U1251B/U1252B User’s and Service Guide Measuring AC voltage 25
2 Making Measurements Measuring DC voltage Figure 2-2 Measuring DC voltage 1 Set the rotary switch to and . 2 Connect the red and black test leads to the input terminals V.mV and COM respectively. 3 Probe the test points and read the display.
Making Measurements 2 Measuring Current µA & mA Measurement 1 Set the rotary switch to . 2 Connect the red and black test leads to the input terminals µA.mA and COM respectively. 3 Probe the test points in series with the circuit, and read the display.
2 Making Measurements % Scale of 4–20 mA The % scale for 4–20 mA or 0–20 mA is calculated using its corresponding DC mA measurement. The meter will optimize the best resolution automatically as shown in the table below. The and bar graph is used for ranging 50 mA and 500 mA. The % scale for 4–20 mA or 0–20 mA is set to two ranges as follows: % (0–20 or 4–20 mA) Always auto range DC mA Auto or manual range 999.99% 50 mA, 500 mA 9999.
Making Measurements 2 A measurement 1 Set the rotary switch to . 2 Connect the red and black test leads to the 10A input terminal A and COM respectively. The meter is set to A measurement automatically when the red test lead is plugged into the A terminal.
2 Making Measurements Frequency Counter WARN IN G • Use the frequency counter for low voltage applications only. Never use the frequency counter for line power system. • For input more than 30 Vpp, you are required to use frequency measurement mode available under the current or voltage measurement instead of frequency counter. 1 Set the rotary switch to . 2 Press to select the Frequency counter (Hz) function. “- 1- “ on the secondary display means the input signal frequency is divided by 1.
Making Measurements 2 Figure 2-6 Agilent U1251B/U1252B User’s and Service Guide Measuring frequency 31
2 Making Measurements Measuring Resistance, Conductance and Testing Continuity CAU T ION Disconnect the circuit power and discharge all high-voltage capacitors before measuring the resistance to any prevent possible damage to the meter or the device under test. 1 Set the rotary switch to . 2 Connect the red and black test leads to the input terminals Ω and COM respectively. 3 Probe the test points (by shunting the resistor) and read the display.
Making Measurements 2 4 Press to scroll through audible continuity, conductance and resistance tests as shown in Figure 2- 8. Audible continuity Press Shift Press Shift Figure 2-8 Agilent U1251B/U1252B User’s and Service Guide Audible continuity, conductance and resistance test.
2 Making Measurements In the range of 0–500 Ω, the beeper will sound if the resistance value falls below 10 Ω. For other ranges, the beeper will sound if the resistance falls below the typical values indicated in the table below. Measuring range Beeper sounds when 500.00 Ω Ω < 10 5.0000 kΩ Ω < 100 50.000 kΩ Ω < 1k 500.00 kΩ Ω < 10k 5.0000 MΩ Ω < 100k 50.000 MΩ Ω < 1M 500.00 MΩ Ω < 10M The conductance measurement enables the measurement of very high resistance of up to 100 GΩ.
Making Measurements 2 Figure 2-9 Agilent U1251B/U1252B User’s and Service Guide Conductance measurement 35
2 Making Measurements Testing Diodes CAU T ION Disconnect the circuit power and discharge all the high-voltage capacitors before testing the diodes to prevent any possible damage to the meter. To test the diodes, turn the circuit power off, and remove the diodes from the circuit. Then proceed as follows: 1 Set the rotary switch to . 2 Connect the red and black test leads to the input terminals and COM respectively.
Making Measurements 2 Figure 2-10 Measuring forward bias of diode Agilent U1251B/U1252B User’s and Service Guide 37
2 Making Measurements .
Making Measurements 2 Measuring Capacitance CAU T ION Disconnect the circuit power and discharge all the high-voltage capacitors before measuring the capacitance to prevent any possible damage to the meter or the device under test. To confirm that the capacitors have discharged, use the DC voltage function. The meter measures capacitance by charging the capacitor with a known current for a period of time, measuring the voltage and then calculating the capacitance.
2 Making Measurements Measuring Temperature CAU T ION Do not bend the thermocouple leads at sharp angles. Repeated bending over a period of time may break the leads. The bead type thermocouple probe is suitable for making temperature measurements between –20 °C to 200 °C in Teflon compatible environments. Above this temperature, the probe may emit a toxic gas. Do not immerse this thermocouple probe in liquids.
Making Measurements 2 4 Touch the measurement surface with the thermocouple probe. 5 Read the display. If you are working in a varied environment, where the ambient temperature is not constant, do the following: 1 Press to select 0 °C compensation. This gives a quick measurement of the relative temperature. 2 Avoid contact between the thermocouple probe and the measurement surface. 3 After a constant reading is obtained, press to set the reading as the relative reference temperature.
2 Making Measurements Figure 2-12 Surface temperature measurement 42 Agilent U1251B/U1252B User’s and Service Guide
Making Measurements 2 Alerts and Warning During Measurement Overload Alert WARN IN G For your safety, look out for this alert. When you are alerted, immediately remove the test leads from the measuring source. The meter provides an overload alert for voltage measurement in both auto and manual range modes. The meter beeps periodically once the measuring voltage exceeds 1010 V. For your safety, please be aware of this alert.
2 Making Measurements Charge Terminal Alert The meter sounds an alert beep when the terminal detects a voltage level of more than 5 V and the rotary switch is not set to the corresponding location. The primary display indicates a flashing “Ch.Err” until the lead is removed from the input terminal. See Figure 2- 14.
Agilent U1251B and U1252B Handheld Digital Multimeter User’s and Service Guide 3 Features and Functions Dynamic Recording 46 Data Hold (Trigger Hold) 48 Refresh Hold 49 Null (Relative) 51 Decibel Display 53 1 ms Peak Hold 55 Data Logging 57 Manual Logging 57 Interval Logging 59 Reviewing Logged Data 61 Square Wave Output (for U1252B) 63 Remote Communication 67 This chapter contains detailed information on the features and functions that are available in this meter.
3 Features and Functions Dynamic Recording The Dynamic Recording mode detects intermittent turn on or turn off voltage or current surges and verifies the measuring performance without the user being present during any particular period of time. You can take readings simultaneously while performing other task. Use the average reading procedure to even out unstable inputs, estimating the percentage in time a circuit is operated, and verifying the circuit performance.
Features and Functions 3 Press to restart Press Max Min for > 1 sec Press Max Min Press Max Min for > 1 sec or press for > 1 sec Press Max Min Press Max Min for > 1 sec or press for > 1 sec Press Max Min Press Max Min for > 1 sec or press for > 1 sec Figure 3-1 Dynamic recording mode operation Agilent U1251B/U1252B User’s and Service Guide 47
3 Features and Functions Data Hold (Trigger Hold) The data hold function allows the user to freeze the displayed digital value. 1 Press to freeze the displayed value and to enter the manual trigger mode. TRIG is displayed. 2 Press again to freeze the next value being measured. TRIG flashes before the new value is updated on the display. 3 Press and hold quit this mode. or for more than 1 second to Press Press Measurement update Press press Figure 3-2 48 or for > 1 sec.
Features and Functions 3 Refresh Hold The hold function allows the user to hold the displayed digital value. The bar- graph is not held, fix proportional to real measurement value. Use the setup mode to activate the Refresh Hold when working on a difficult measuring field. This function will auto trigger or update the Hold value with a new measuring value, and sound a tone to remind the user. Press to enter the Refresh Hold mode. The present value holds, and the sign lights up.
Features and Functions 3 Press Variation counts > setting The HOLD sign flashes until the measured value is stable and updated Measurement is updated Figure 3-3 N O TE Refresh hold mode operation • For voltage and current measurements, the holding value will not be updated if the reading is below 500 counts. • For resistance and diode measurements, the holding value will not be updated if the reading is in “OL” (open state).
Features and Functions 3 Null (Relative) The Null function subtracts a stored value from the present measurement and displays the difference between the two. 1 Press to store the displayed reading as the reference value to be subtracted from subsequent measurements and to set the display to zero. NULL is displayed. N O TE Null can be set for both auto and manual range settings, but not in the event of an overload. 2 Press to see the stored reference value.
3 Features and Functions Press Press Auto-return after 3 seconds Flash Press as NULL is flashing on the display Figure 3-4 52 Null (relative) mode operation Agilent U1251B/U1252B User’s and Service Guide
Features and Functions 3 Decibel Display The dBm operation calculates the power delivered to a reference resistance relative to 1 mW, and can be applied to DC V, AC V and AC + DC V measurements for decibel conversion. The voltage measurement is converted to dBm by using the following formula: The reference resistance may be selected from 1~9999Ω in Setup mode. The default value is 50 Ω. The decibel of voltage is calculated with respect to 1 V.
3 Features and Functions Press Only when rotary switch is at position Press Press Press for > 1 sec. for > 1 sec. Press Press Press Only when rotary switch is at position Press Press Press Figure 3-5 54 for > 1 sec.
Features and Functions 3 1 ms Peak Hold This function allows the measurement of half- cycle peak voltage for the the analysis of components such as power distribution transformers and power factor correction capacitors. The peak voltage obtained can be used to determine the crest factor: Crest factor = Peak value/True RMS value 1 Press for more than 1 second to toggle 1 ms Peak Hold mode ON / OFF. 2 Press to scroll through maximum and minimum peak readings.
3 Features and Functions Press for > 1 sec.
Features and Functions 3 Data Logging The Data logging function makes it easy to record test data for future review or analysis. Since data are stored in the non- volatile memory, they are retained when the meter is turned OFF or when the battery is changed. There are two options - hand (manual) logging and interval (automatic) logging. Data logging records the values on primary display only. Manual Logging Hand (Manual) logging can be specified in Setup mode.
3 Features and Functions Press for > 1 sec. Press for > 1 sec. Auto-return after 3 seconds Figure 3-7 N O TE Hand (Manual) logging mode operation The maximum data that can be stored is 100 entries. When the 100 entries are filled, the secondary display indicates “FULL”, as shown in Figure 3-8. Press for > 1 sec. Auto-return after 3 seconds Figure 3-8 3 Press 58 Full Log for more than 1 second to exit this mode.
Features and Functions 3 Interval Logging Interval (automatic) logging mode can be specified in the Setup mode. 1 Press for more than 1 second to store the present value and function on the primary display into the non- volatile memory. and the logging index are indicated. The readings are automatically saved into the permanent memory at intervals set using the Setup mode. N O TE The maximum data that can be stored is 200 entries.
3 Features and Functions Press for > 1 sec. First interval Press for > 1 sec. Last interval Press for > 1 sec.
Features and Functions 3 Reviewing Logged Data 1 Press for more than 1 second to enter the Log Review mode. The last recorded entry and the last logging index are displayed. 2 Press to switch between hand (manual) and interval (automatic) logging review mode. 3 Press to ascend or to descend through the logged data. Press to select the first record and press to select the last record for quick navigation. 4 Press for more than 1 second at the respective Log Review mode to clear logged data.
3 Features and Functions Press View for > 1 sec.
Features and Functions 3 Square Wave Output (for U1252B) The square wave output is a unique function for many applications, such as PWM (Pulse Width Modulation) output, adjustable voltage control, and synchronic clock (baud rate generator). You can also use this function to check and calibrate flow- meter displays, counters, tachometers, oscilloscopes, frequency converter, frequency transmitter and other frequency input devices. 1 Turn the rotary switch to position.
3 Features and Functions Press Press Press Press Set Hz Figure 3-11 Frequency adjustment for square wave output 5 Press display. to select the pulse width (%) on the primary 6 Press or to adjust the pulse width. The pulse width can be set for 256 steps and each step is 1/ (256 x Frequency). The display range automatically adjusts in the range of 9.9999~9999.9 ms.
Features and Functions 3 Press Press Press Press Figure 3-12 Duty cycle adjustment for square wave output Agilent U1251B/U1252B User’s and Service Guide 65
3 Features and Functions Press Press Set % Press Set % Press Figure 3-13 Pulse width adjustment for square wave 66 Agilent U1251B/U1252B User’s and Service Guide
Features and Functions 3 Remote Communication The meter has a bi- directional (full duplex) communication capability that speeds data storing from the meter to the PC. To use this feature, you require the optional IR- USB cable, to be used with an application software that is downloadable from the Agilent Web site. For details on performing PC- meter remote communication, click on Help after launching the Agilent GUI Data Logger Software.
3 Features and Functions To PC USB Figure 3-14 Cable connection for remote communication 68 Agilent U1251B/U1252B User’s and Service Guide
Agilent U1251B and U1252B Handheld Digital Multimeter User’s and Service Guide 4 Changing The Default Setting Selecting Setup Mode 70 Setting Data Logging Mode 74 Setting Thermocouple Types (for U1252B) 75 Setting Reference Impedance for dBm Measurement 76 Setting Minimum Frequency Measurement 77 Setting Temperature Unit 78 Setting Auto Power Saving Mode 80 Setting % Scale Readout 82 Setting Beep Frequency 83 Setting Backlit Timer 84 Setting Baud Rate 85 Setting Parity Check 86 Setting Data Bit 87 Setting
4 Changing The Default Setting Selecting Setup Mode To enter the Setup mode, perform the following steps: 1 Turn the meter OFF. 2 From the OFF position, press and hold while turning the rotary switch to any non- OFF position. N O TE When you hear a beep, the meter is in Setup mode and you can release . To change a menu item setting in Setup mode, perform the following steps: 1 Press or to scroll through the menu items. 2 Press or to scroll through the available settings.
Changing The Default Setting 4 Table 4-1 Available setting options in Setup mode Menu item Available setting options Display Description Display rHoLd (1) Refresh Hold OFF 100–1000 d-LoG Data logging Hand 1–9999 s (2) t.
4 Changing The Default Setting Available setting options Menu item Display Default factory setting Description Display Description Print Print On, OFF Enables auto send of data to the PC continuously when set to On OFF rESEt Reset dEFAU Enables the reset of factory settings by pressing dEFAU and holding Temperature (4) d-CF Sets the temperature measurement to °C but pressing Sets the temperature measurement to °F d-FC Sets the temperature measurement to °F but d-C Battery voltage Fi
Changing The Default Setting 4 Setting Data Hold/Refresh Hold Mode 1 Set OFF to enable the Data Hold mode (manual trigger by key or bus via the remote control). 2 Set the variation count within the 100~1000 range to enable the Refresh Hold mode (automatic trigger). When the variation of the measuring value exceeds the setting of the variation count, the Refresh Hold will be ready to trigger.
4 Changing The Default Setting Setting Data Logging Mode 1 Set to “Hand” to enable the hand (manual) data logging mode. 2 Set the interval within 0001~9999 seconds to enable interval (automatic) data logging mode. 3 Press or to switch between manual and interval data logging setup.
Changing The Default Setting 4 Setting Thermocouple Types (for U1252B) The types of thermocouple sensor that can be selected are the J and the K types. The default type is the K type. Press or to switch between the J and the K type.
4 Changing The Default Setting Setting Reference Impedance for dBm Measurement The reference impedance can be set from 1 to 9999 default value is 50 W. W .
Changing The Default Setting 4 Setting Minimum Frequency Measurement The minimum frequency setup influences the measuring rates for frequency, duty cycle, and pulse width. The typical measuring rate defined at the general specification is based on the minimum frequency of 1 Hz.
4 Changing The Default Setting Setting Temperature Unit Four combination displays are available: • Celsius only (°C on primary display) single display setting • Celsius- Fahrenheit (d- CF) and Fahrenheit- Celsius (d- FC) dual display setting. N O TE Primary-Secondary Display can be swapped by pressing . • Fahrenheit only (°F on primary display) single display setting.
Changing The Default Setting 4 Press Press Press Press Press Figure 4-6 Agilent U1251B/U1252B User’s and Service Guide Temperature unit setup 79
4 Changing The Default Setting Setting Auto Power Saving Mode • The timer for APF (Auto Power OFF) can be set for the range of 1~99 minutes. To activate the meter after it has “auto power off”, turn the rotary switch to the OFF position, then turn it back on again. • “OFF” disables APF. is indicated on the display during subsequent measurements.
Changing The Default Setting 4 Press Press Press Press Press Figure 4-7 Agilent U1251B/U1252B User’s and Service Guide Auto power saving setup 81
4 Changing The Default Setting Setting % Scale Readout This setting converts the DC current measuring display to % scale readout — 4- 20 mA or 0- 20 mA as proportional to 0~100%. The 25% scale readout represents DC 8 mA at 4- 20 mA and DC 5 mA at 0- 20 mA.
Changing The Default Setting 4 Setting Beep Frequency • The driving frequency can be set to 2400, 1200, 600 or 300 Hz. “OFF” disables beep.
4 Changing The Default Setting Setting Backlit Timer • The timer can be set to 1~99 seconds. Backlit turns off automatically after the set period. • “0FF” disables turning off backlit automatically.
Changing The Default Setting 4 Setting Baud Rate Select the baud rate for remote control. The available settings are 2400, 4800, 9600 and 19200 Hz.
4 Changing The Default Setting Setting Parity Check Select the parity check for remote control. It can be set to none, even or odd bit.
Changing The Default Setting 4 Setting Data Bit Select the data bit for remote control. It can be set to either 8 or 7 bits.
4 Changing The Default Setting Setting Echo Mode • Echo ON enables the return of characters to the PC in remote communication. • Echo OFF disables the return of characters to the PC.
Changing The Default Setting 4 Setting Print Mode Print ON enables the print out of measured data to the PC when the measuring cycle is completed. In this mode, the meter automatically sends the newest data to the host continuously but does not accept any commands from thehost. flashes during the Print operation.
4 Changing The Default Setting Returning to Default Factory Settings • Press for more than 1 second to reset to the default factory settings except the Temperature setting. • The Reset menu item automatically reverts to Refresh Hold menu item after reset has taken place. Press for > 1 sec.
Changing The Default Setting 4 Setting the Battery Voltage The battery type for the multimeter can be set to either 7.2 V or 8.4 V.
4 Changing The Default Setting Setting the DC Filter This setting is used to filter AC signal in DC measuring path. The DC filter is set to “OFF” by default. To enable this function, set this to “On”. Press Figure 4-18 DC filter N O TE • When DC filter is enabled, the measurement speed may decrease during DC voltage measurement. • During AC or Hz measurement (on primary or secondary display), DC filter will be automatically disabled.
Agilent U1251B and U1252B Handheld Digital Multimeter User’s and Service Guide 5 Maintenance Introduction 94 General Maintenance 94 Replacing the Battery 95 Charging the Battery 97 Replacing the Fuse 103 Troubleshooting 105 This chapter helps you to troubleshoot a failing handheld digital multimeter.
5 Maintenance Introduction Repair or service which is not covered in this manual should only be performed by a qualified personnel. General Maintenance WARN IN G Ensure that the terminal connections are correct for that particular measurement before proceeding. To avoid damaging the device, do not exceed the input limit. Besides the above hazard, dirt or moisture in the terminals can distort readings. The steps for cleaning are as follows: 1 Turn the meter off and remove the test leads.
Maintenance 5 Replacing the Battery WARN IN G Never discharge the battery by shorting it or by reverse polarity in any subjects. Make sure that the battery is the rechargeable type before charging it. Never rotate the rotary switch when the battery is being charged as DC at 24 V is being applied to the charging terminals. The meter is powered by a 7.2 V battery. Use only the specified type.
5 Maintenance 2 Slide down the battery cover. 3 Lift the battery cover up. 4 Replace the specified battery. 5 Reverse the above procedures to close the cover. N O TE List of compatible batteries for the Agilent U1251B : • 9V Alkaline non-chargeable battery (ANSI/NEDA 1604A or IEC 6LR61) • 9V Carbon-zinc non-chargeable battery (ANSI/NEDA 1604D or IEC6F22) List of compatible batteries for the Agilent U1252B : • 7.2V 300mAH Ni-MH Rechargeable battery, 9V size • 8.
Maintenance 5 Charging the Battery WARN IN G Never discharge the battery by shorting it or by reverse polarity in any subjects. Make sure the battery is the rechargeable type before charging it. Never rotate the rotary switch when the battery is being charged as DC at 24 V is being applied to the charging terminals. CAU T ION • Do not rotate the rotary switch from charging the battery. position when • Perform battery charging only with 7.2 V or 8.4 V NiMH rechargeable battery, 9 V size.
5 Maintenance respectively. The DC adaptor can be replaced with a DC power supply in order to set the 24 V DC output and the over current limitation to a value more than 0.5 A. Ensure that the polarity of the connection is correct. 4 The primary display indicates “bAt” and the ‘SbY” flashes on the secondary display and a short tone sounds to remind you whether to charge the battery or not.
Maintenance 5 5 After pressing Shift or when the self- test starts, the meter performs a self- test to check if the battery in the meter is the rechargeable type. The self- test takes about 2 to 3 minutes. Avoid pressing any button during the self- test. A message is diplayed as shown below.
5 Maintenance Error Condition Secondary Display C-Err • No rechargeable battery inside • Battery failing Figure 5-3 N O TE Error messages • If the OL message appears while the battery is inside, do not charge the battery. • If the C-Err message appears, check if the battery is the specified type. Use the battery as specified in this guide. Ensure that the battery is the correct rechargeable type before charging it again.
Maintenance Figure 5-4 5 Charging mode 6 The charge end message (C–End) appears on the secondary display once charging is completed. The trickle charging current is provided to maintain the battery capacity. The flashing signs of and appear to show the trickle state. 7 Remove the DC adapter when the C–End message appears on the secondary display. Do not turn the rotary switch before removing the adapter from the terminals.
5 Maintenance Press to start charge Error Error-Full Error-Empty Battery can be charged Fully charged Figure 5-6 102 Battery charging procedures Agilent U1251B/U1252B User’s and Service Guide
Maintenance 5 Replacing the Fuse N O TE This manual provides only the fuse replacement procedures, but not the fuse replacement markings. Follow the procedures below to replace the fuse. 1 Turn the meter off and disconnect the test leads from the external equipment. Make sure to remove the adaptor. 2 Wear clean/dry gloves and do not touch any other component except the fuse and plastic parts. The current calibration is considered shunt only, so do not recalibrate the meter after replacing the fuse.
5 Maintenance Fuse 1 Fuse 2 Figure 5-7 Fuse replacement 104 Agilent U1251B/U1252B User’s and Service Guide
Maintenance 5 Troubleshooting WARN IN G To avoid electrical shock, do not perform any service unless you are qualified to do so. If the instrument fails to operate, check the battery and the test leads. Replace them if necessary. And if the instrument still does not function, check the operating procedures in this manual. When servicing, use only specified replacement parts. The table below will assist you to identify some basic problems.
5 106 Maintenance Agilent U1251B/U1252B User’s and Service Guide
Agilent U1251B and U1252B Handheld Digital Multimeter User’s and Service Guide 6 Performance Tests and Calibration Calibration Overview 108 Recommended Test Equipment 110 Basic Operating Test 111 Test Considerations 114 Performance Verification Tests 116 Calibration Security 124 Calibration Process 128 Adjustments Consideration 130 This chapter contains the performance test procedures and the adjustment procedures.
6 Performance Tests and Calibration Calibration Overview This manual contains procedures to verify the instrument’s performance and adjustment (calibration). N O TE Make sure you have read the “Test Considerations” on page 114 before calibrating the instrument. Closed-case Electronic Calibration This instrument features closed- case electronic calibration. No internal mechanical adjustments are required. The instrument calculates correction factors based upon the input reference value you set.
Performance Tests and Calibration 6 Adjustment is Recommended Specifications are only guaranteed within the period stated from the last adjustment. Agilent recommends that readjustment should be performed during the calibration process for best performance. This will assure that the U1251B/U1252B will remain within the specifications for the next calibration interval. This criterion for the re- adjustment provides the best long–term stability.
6 Performance Tests and Calibration Recommended Test Equipment The test equipment recommended for the performance verification and adjustment procedures is listed below. If the exact instrument is not available, substitute calibration standards of equivalent accuracy. A suggested alternative method would be to use the Agilent 3458A 8½ - Digit Digital Multimeter to measure less accurate yet stable sources.
Performance Tests and Calibration 6 Basic Operating Test The Basic Operating Test is to test the basic operability of the instrument. Repair is required if the instrument fails the Basic Operating Test. Backlit Test Press the Bat button to test the backlight. It will momentarily toggle backlit ON and OFF. Testing the Display Press the Hold button and turn on the Meter to view all segments of the display. Compare the display with the example in Table 6- 1.
6 Performance Tests and Calibration Current Terminal Test This test determines if the input warning of the current terminal test is functioning properly. The meter sounds an alert beep when the test lead is inserted into the A terminal but the rotary switch is not set to mA.A function. The primary display will indicate “A- Err”. It is shown in Figure 55. The primary display will keep flashing unless the test lead is removed from “A” terminal.
Performance Tests and Calibration 6 Charge Terminal Alert Test This test determines if the charge terminal alert is operating properly. The meter sounds an alert when the terminal detects a voltage level of more than 5 V and the rotary switch is not set to the position. The meter sounds an alert beep and the primary display flashes the “Ch.Err” until the lead is removed from the terminal.
6 Performance Tests and Calibration Test Considerations Long test leads can also act as antennas which may pick up AC signals. For optimum performance, all procedures should comply with the following recommendations: • Ensure that the calibration ambient temperature is stable and is between 18 °C and 28 °C. Ideally the calibration should be performed at 23 °C ± 1 °C. • Ensure that the ambient relative humidity is less than 80%.
Performance Tests and Calibration 6 Input Connections Test connections to the instrument are best accomplished using the dual banana plug with copper wire short between the two terminals for low- thermal offset measurement. We recommend the use of shielded, twisted- pair, Teflon interconnect cables of minimum length between the calibrator and the multimeter. The cable shields should be earth ground referenced.
6 Performance Tests and Calibration Performance Verification Tests Use the Performance Verification Tests to verify the easurement performance of the instrument. The performance verification tests use the instrument’s specifications listed in the U1251B/U1252B Data Sheet. The performance verification tests are recommended as acceptance tests when you first receive the instrument. The acceptance test results should be compared against the one year test limits.
Performance Tests and Calibration 6 Perform the verification test steps in the following Table 6- 2: Table 6-2 Verification Test Step Test Function Range 5520A Output Error from nominal 1 year U1251B 1 Turn the rotary switch to the position 5V U1252B 5 V, 1 kHz ± 32.5 mV ± 22.5 mV 5 V, 10 kHz ± 52.5 mV ± 32.5 mV 5 V, 20 kHz N/A ± 79.
6 Performance Tests and Calibration Step Test Function Range 5520A Output Error from nominal 1 year U1251B 4 Turn the rotary switch to U1252B 5V 5V ± 2 mV ±1.75 mV 50 V 50 V ± 20 mV ± 17.5 mV 500 V 500 V ± 200 mV ± 200 mV 1000 V 1000 V ± 800 mV ± 800 mV 5V 5 V,1 kHz N/A ± 22.5 mV 5 V, 10 kHz N/A ± 32.5 mV 5 V, 20 kHz N/A ± 79.0 mV 5 V, 100 kHz N/A ± 187 mV 50 V, 1 kHz N/A ± 225 mV 50 V, 10 kHz N/A ± 225 mV 50 V, 20 kHz N/A ± 790 mV 50 V, 100 kHz N/A ± 1.
Performance Tests and Calibration Step Test Function Range 5520A Output Error from nominal 1 year U1251B 6 Turn the rotary switch to the position 7 Press the button to go to [2] U1252B ± 75 μV [2] 50 mV 50 mV ± 75 μV 500 mV 500 mV ± 0.2 mV ± 0.175 mV –500 mV ± 0.2 mV ± 0.175 mV 1000 mV ± 0.8 mV ± 0.75 mV –1000 mV ± 0.8 mV ± 0.75 mV 50 mV, 1 kHz ± 0.34 mV ± 0.24 mV 50 mV, 10 kHz ± 0.54 mV ± 0.39 mV 50 mV, 20 kHz N/A ± 0.415 mV 50 mV, 30 kHz ± 0.
6 Performance Tests and Calibration Step Test Function Range 5520A Output Error from nominal 1 year U1251B 8 Turn the rotary switch to the W position 9 Press mode button to go to ns 10 Turn the rotary switch to the Hz/ position (for model U1252B), to position (for model U1251B) U1252B 500 W 500 W ± 500 mW [3] ± 350 mW [3] 5 kW 5 kW ± 4.5 W [3] ± 3 W [3] 50 kW 50 kW ± 45 W ± 30 W 500 kW 500 kW ± 450 W ± 300 W 5 MW 5 MW ± 10.5 kW ± 8 kW 50 MW [4] 50 MW ± 0.510 MW ± 0.
Performance Tests and Calibration Step Test Function Range 5520A Output Error from nominal 1 year U1251B 14 Press button to go to mode[8] 15 16 Turn the rotary swich to the position Press button to go to 6 U1252B 100.00 μF 100.00 μF ± 1.05 μF ± 1.05 μF 1000.0 μF 1000.0 μF ± 10.5 μF ± 10.5 μF 10.00 mF 10.00 mF ± 0.105 mF ± 0.105 mF 100.00 mF 10.00 mF ± 0.4 mF ± 0.4 mF –200 ºC until 1372 ºC 0 ºC ± 3 ºC ± 3 ºC 100 ºC ± 3.3 ºC ± 3.3 ºC 500 μA 500 μA ± 0.55 μA[9] ± 0.
6 Performance Tests and Calibration Step Test Function Range 5520A Output Error from nominal 1 year U1251B 19 Press button to go to U1252B 5A 5 A, 1 kHz ± 42 mA ± 37 mA 3A 3 A, 5 kHz ± 96 mA ± 96 mA 10 A[11] 10 A, 1 kHz ± 100 mA ± 90 mA Square Wave Output Use 53131A 120 Hz @ 50% N/A ± 26 mHz 4800 Hz @ 50% N/A ± 260 mHz 100 Hz @ 50% N/A ± 0.398%[12] 100 Hz @ 25% N/A ± 0.398%[12] 100 Hz @ 75% N/A ± 0.398%[12] N/A ± 0.
Performance Tests and Calibration 6 [8] The accuracy does not include the tolerance of the thermocouple probe. The thermal sensor plugged into the meter should be placed in the operating enviroment for at least an hour. Use the Null function to reduce the thermal effect. [9] Always use relative function to zero the thermal effect with open test lead before measuring the signal. If you do not use Relation function, add 20 digits for accuracy purposes. [10] 10A continuous, and additional 0.
6 Performance Tests and Calibration Calibration Security The calibration security code prevents accidental or unauthorized adjustments to the instrument. When you first receive your instrument, it is secured. Before you can adjust the instrument, you must unsecure it by entering the correct security code (see “Unsecuring the Instrument for Calibration” on page 125). The security code is set to 1234 when the instrument is shipped from the factory.
Performance Tests and Calibration 6 Unsecuring the Instrument for Calibration Before you can adjust the instrument, you must unsecure it by entering the correct security code. The security code is set to 1234 when the instrument is shipped from the factory. The security code is stored in non- volatile memory, and does not change when power is off. To Unsecure the Instrument from the Front Panel 1 Turn the rotary switch to .
6 Performance Tests and Calibration To Change the Instrument Calibration Security Code from the Front Panel 1 When the multimeter is in the unsecured mode, press for more than 1 second to enter the Calibration Security Code setting mode. 2 The factory default calibration security code 1234 will be displayed on the primary display. 3 Use the editing keys character in the code. 4 Use the the code. 5 Press code.
Performance Tests and Calibration 6 To Unsecure the Instrument Without the Security Code To unsecure the instrument without the correct security code, follow the steps below. N O TE If you do not have a record of the security code, you can try 1234 (the factory default code) using the front panel or the remote interface. 1 Record the last 4 digits of the multimeter’s serial number. 2 Turn the rotary switch to . 3 Press and simultaneously to enter the Calibration Security Code entry mode.
6 Performance Tests and Calibration Now you can use 1234 as the security code. If you want to enter a new security code, see “To Change the Instrument Calibration Security Code from the Front Panel” on page 126. Make sure you record the new security code. Calibration Process To complete a full instrument calibration use following general procedures: 1 Read “Test Considerations” on page 114. 2 Perform the verification tests to characterize the instrument (incoming data).
Performance Tests and Calibration 6 Using the Front Panel for Adjustments This section describes the procedures to perform adjustments from the front panel. Selecting the Adjustment Mode To unsecure the instrument, see “Unsecuring the Instrument for Calibration” on page 125 or “To Unsecure the Instrument Without the Security Code” on page 127. Once unsecured, the reference value will be indicated on the primary display.
6 Performance Tests and Calibration Adjustments Consideration You will need a test input cable, a connectors set, and a Shorting Plug to adjust the instrument (see “Input Connections” on page 115). N O TE After each adjustment, the secondary display briefly shows PASS. If the calibration fails, the handheld multimeter sounds a beep, and an error number is shown in the secondary display. Calibration error messages are described on page 140.
Performance Tests and Calibration 6 Valid Adjustment Input Values Adjustment can be accomplished using the following input values below. Table 6-3 Valid adjustment input values Function Range Valid Amplitude Input Values 5V, 50 V, 500 V, 1000 V 0.9 to 1.1 x Full Scale 5 V, 50 V, 500 V, 1000 V 0.9 to 1.1 x Full Scale 5 V, 50 V ,500 V, 1000 V 0.9 to 1.1 x Full Scale 50 mV, 500 mV, 1000 mV 0.9 to 1.1 x Full Scale 500 µA, 5000 µA 0.9 to 1.1 x Full Scale 50 mA, 440 mA, 5 A, 10 A 0.9 to 1.
6 Performance Tests and Calibration Adjustment Procedure Review the sections “Test Considerations” on page 114 and “Adjustments Consideration” on page 130 before proceeding with this procedure. 1 Turn the rotary switch to “Test Function” position as shown in the adjustment table. 2 After unsecuring the instrument, the instrument goes into the adjustment mode.
Performance Tests and Calibration 6 For an adjustment that is successful, the secondary display will briefly show PASS. An adjustment failure is indicated by a long beep and a calibration error number appears in the secondary display. The primary display remains at the current Cal Item. Check the input value, range, function, and entered adjustment value to fix the problem. Repeat the adjustment procedure. 9 Repeat steps 1 through 8 for each adjustment point.
6 Performance Tests and Calibration Table 6-4 Adjustment table Step 1 Test Function Turn the rotary switch to the position Cal Range U1252B 0.3 V,1 kHz 0.3000 V 0.3000 V 3 V, 1 kHz 3.0000 V 3.0000 V 3 V, 10 kHz 3.0000 V 3.0000 V 3 V, 1 kHz 03.000 V 03.000 V 30 V, 1 kHz 30.000 V 30.000 V 30 V, 10 kHz 3.0000 V 30.000 V 30 V,1 kHz 030.00 V 030.00 V 300 V,1 kHz 300.00 V 300.00 V 300 V, 10 kHz 3.0000 V 300.00 V 30 V, 1 kHz 0030.0 V 0030.0 V 300 V, 1 kHz 0300.0 V 0300.
Performance Tests and Calibration Step 3 Test Function Press the Cal Range button to go to Cal Item U1251B U1252B 0.3 V, 1 kHz N/A 0.3000 V 3 V, 1 kHz N/A 3.0000 V 3 V, 10 kHz N/A 3.0000 V 3 V, 1 kHz N/A 03.000 V 30 V, 1 kHz N/A 30.000 V 30 V, 10 kHz N/A 30.000 V 30 V, 1 kHz N/A 030.00 V 300 V, 1 kHz N/A 300.00 V 300 V, 10 kHz N/A 300.00 V 30 V, 1 kHz N/A 0030.0 V 300 V, 1 kHz N/A 0300.0 V 300 V, 10 kHz N/A 0300.
6 Performance Tests and Calibration Step 5 Test Function Press the Cal Range button to go to U1252B 3 mV, 1 kHz 03.000 mV 03.000 mV 30 mV, 1 kHz 30.000 mV 30.000 mV 30 mV, 10 kHz 30.000 mV 30.000 mV 30 mV, 1 kHz 030.00 mV 030.00 mV 300 mV, 1 kHz 300.00 mV 300.00 mV 300 mV, 10 kHz 30.000 mV 300.00 mV 30 mV, 1 kHz 0030.0 mV 0030.0 mV 1000 mV, 1 kHz 1000.0 mV 1000.0 mV 1000 mV, 10 kHz 30.000 mV 1000.
Performance Tests and Calibration Step 7 8 Test Function Cal Range Cal Item U1251B U1252B Turn the rotary switch to the Hz/ position (for model U1252B), to position (for model U1251B) Short Dual banana shorting plug with copper wire SHORT SHORT 2V 2V 2.0000 V 2.0000 V Turn the rotary switch to the Open Input terminal open (remove any test leads and Short Plugs from the input terminal) oPEn oPEn 10 nF 3 nF 03.000 nF 03.000 nF 10 nF 10.000 nF 10.000 nF 10 nF 010.00 nF 010.
6 Performance Tests and Calibration Step 11 Test Function Press Cal Range button to go to U1252B 30 µA,1 kHz 030.00 µA 030.00 µA 300 µA,1 kHz 300.00 uA 300.00 µA 300 µA,1 kHz 0300.0 µA 0300.0 µA 3000 µA, 1 kHz 3000.0 µA 3000.0 µA Open Input terminal open (remove any test leads and Short Plugs from the input terminal) oPEn oPEn 50 mA 30 mA 30.000 mA 30.000 mA 440 mA 300 mA 300.00 mA 300.
Performance Tests and Calibration 6 Finishing the Adjustment 1 Remove all the shorting plugs and connectors from the instrument. 2 Record the new Calibration Count. 3 Press and simultaneously to exit the Adjustment Mode. Power off and on again. The instrument will then be secured. To Read the Calibration Count You can query the instrument to determine how many calibrations have been performed. N O TE Your instrument was calibrated before it left the factory.
6 Performance Tests and Calibration Calibration Errors The following errors indicate failures that may occur during a calibration.
Agilent U1251B and U1252B Handheld Digital Multimeter User’s and Service Guide 7 Specifications DC Specifications 142 U1251B AC Specifications 144 U1252B AC Specifications 145 U1252B AC+DC Specifications 146 Temperature and Capacitance Specifications 147 U1251B & U1252B Frequency Specifications 148 Operating Specifications 152 General Specifications 154 This chapter lists the specifications of the handheld digital multimeter.
7 Specifications DC Specifications Table 7-1 DC Accuracy ± (% of reading + No. of Least Significant Digit) Function Voltage [1] Resistance[8] Range 50.000 mV Resolution 0.001 mV Test Current/ Burden Voltage - 500.00 mV 1000.0 mV 5.0000 V 50.000 V 500.00 V 1000.0 V 0.01 mV 0.1 mV 0.0001 V 0.001 V 0.01 V 0.1 V 0.01 Ω 1.04 mA 500.00 Ω[3] 0.025+5 0.03+5 0.03+5 0.08+10 0.05+10 0.08+5 0.05+5 0.15+5 1+5 416 μA 41.2 μA 4.12 μA 375 nA 187 nA 500.00 MΩ[4] 0.01 MΩ 187 nA 0.2+5 1+10 - 500.
Specifications 7 [1] Input impedance: Refer to Table 7-6. [2] The accuracy could be 0.05 %+10 for U1251B and 0.05 %+5 for U1252B. Always use the Null function to zero out the thermal effect before measuring the signal. [3] The accuracy of 500 Ω and 5 kΩ is specified after Null function, which is used to subtract the test lead resistance and the thermal effect [4] For the range of 50 Ω/500 MΩ, the R.H. is specified for <60 %.
7 Specifications U1251B AC Specifications Table 7-2 U1251B AC Accuracy ± (% of reading + No. of Least Significant Digit) Function True RMS AC Voltage [1][2] Range 50.000 mV 500.00 mV 1000.0 mV 5.0000 V 50.000 V 500.00 V Resolution 0.001 mV 0.01 mV 0.1 mV 0.0001 V 0.001 V 0.01 V 1000.0 V 0.1 V 30 Hz to 45 Hz 1+60 1+60 1+60 1+60 1+60 1+60 Frequency 45 Hz to 1 kHz 1 kHz to 10 kHz 0.6+40 1.0+40 0.6+25 1.0+40 0.6+25 1.0+25 0.6+25 1.0+25 0.6+25 1.0+25 0.6+25 1.0+25 1+60 0.6+40 1.
Specifications 7 U1252B AC Specifications Table 7-3 U1252B AC Accuracy ± (% of reading + No. of Least Significant Digit) Frequency 0.001 mV 0.01 mV 0.1 mV 0.0001 V 0.001 V 0.01 V 20 Hz – 45 Hz 1.5+60 1.5+60 1.5+60 1.5+60 1.5+60 1.5+60 45 Hz – 1 kHz 0.4+40 0.4+25 0.4+25 0.4+25 0.4+25 0.4+25 1 kHz – 10 kHz 0.7+40 0.4+25 0.4+25 0.6+25 0.4+25 0.4+25 10 kHz – 20 kHz 0.75+40 0.75+40 0.75+40 1.5+40 1.5+40 1.5+40 0.1 V 1.5+60 0.4+40 0.4+40 1.5+40[3] Function Range Resolution True RMS AC Voltage 50.
7 Specifications U1252B AC+DC Specifications Table 7-4 U1252B AC Accuracy ± (% of reading + No. of Least Significant Digit) Frequency Function Range Resolution Voltage[2] 50.000 mV 500.00 mV 1000.0 mV 5.0000 V 50.000 V 500.00 V 0.001 mV 0.01 mV 0.1 mV 0.0001 V 0.001 V 0.01 V 1000.0 V 30 Hz – 45 Hz 1.5+80 1.5+65 1.5+65 1.5+65 1.5+65 1.5+65 0.1 V 1.5+65 Function Range Resolution Current 500.00 μA[4] 0.01 μA 0.1 μA 0.001 mA 0.01 mA 0.0001 A 5000.0 μA 50.000 mA 440.00 mA 5.0000 A 10.
Specifications 7 Temperature and Capacitance Specifications Function Thermocouple Type Range K -200 – 1372 °C/ -328 – 2502 °F -210 – 1200 °C/ -346 – 2192 °F Temperature[1] J(2) Function Range Resolution Resolution 0.1 °C/ 0.1 °F 0.1 °C/ 0.1 °F Accuracy ± (% of reading + Offset Capacitance 10.000 nF 100.00 nF 1000.0 nF 10.000 μF 100.00 μF 1000.0 μF 10.000 mF 100.00 mF Accuracy ± (% of reading + No. of 0.001 nF 0.01 nF 0.1 nF 0.001 μF 0.01 μF 0.1 μF 0.001 mF 0.
7 Specifications U1251B & U1252B Frequency Specifications Range Resolution [1] Accuracy Min. Input Frequency ± (% of reading + No. of Least Significant Digit) 99.999 Hz 999.99 Hz 9.9999 kHz 99.999 kHz 999.99 kHz 0.001 Hz 0.01 Hz 0.0001 kHz 0.001 kHz 0.01 kHz 0.02%+3 <600 kHz 1 Hz U1251B Frequency Sensitivity During Voltage Measurement Input Range (Maximum input for specified accuracy = 10 x Range or 1000 V) 50.000 mV 500.00 mV 1000.0 mV 5.0000 V 50.000 V 500.00 V 1000.
Specifications 7 U1251B & U1252B Frequency Sensitivity During Current Measurement Input Range Minimum Sensitivity (R.M.S. Sine-Wave) 20 Hz – 20 kHz 100 μA 250 μA 10 mA 25 mA 1A 2.5 A 500.00 μA 5000.0 μA 50.000 mA 440.00 mA 5.0000 A 10.000 A Duty Cycle [1] MODE RANGE ACCURACY AT FULL SCALE DC Coupling 0.01 % – 99.99 % 0.3 % per kHz + 0.3 % MODE RANGE ACCURACY AT FULL SCALE 500 ms 2000 ms 0.01 ms 0.1 ms 0.2 % + 3 0.
7 Specifications U1252B Frequency Counter Specifications Divide 1 (secondary display “-1-”) Range Resolution Accuracy ± (% of reading + No. of Least Significant Digit) 99.999 Hz 0.001 Hz 0.02%+3[2] 999.99 Hz 9.9999 kHz 99.999 kHz 999.99 kHz 9.9999 MHz 0.01 Hz 0.0001 kHz 0.001 kHz 0.01 kHz 0.0001 MHz Sensitivity Min. Input Frequency 100 mV R.M.S. 0.5 Hz 0.002%+5, <985 kHz 200 mV R.M.S. Divide 100 (secondary display “-100-”) Range Resolution Accuracy ± (% of reading + No.
Specifications 7 U1252B SQUARE WAVE OUTPUT OUTPUT[1] RANGE RESOLUTION ACCURACY FREQUENCY 0.5, 1, 2, 5, 10, 15, 20, 25, 30, 40, 50, 60, 75, 80, 100, 120, 150, 200, 240, 300, 400, 480, 600, 800, 1200, 1600, 2400, 4800 Hz 0.39% – 99.60% 0.01Hz 0.005% +2 0.390625% 1/Frequency Range/256 0.4% of full scale[3] 0.2 ms + Range/256 Fixed 0 to +2.8 V 0.1 V 0.2 V DUTY CYCLE[2] [4] WIDTH[2][4] PULSE AMPLITUDE [1] Output impedance: 3.5 kW maximum.
7 Specifications Operating Specifications Measuring rate Table 7-5 Measuring rate 152 Function Times/second ACV 7 ACV + dB 7 DCV 7 ACV 7 AC + DC V 2 Ω/nS 14 Diode 14 Capacitance 4 (< 100 μF) DCI 7 ACI 7 AC + DC I 2 Temperature 6 Frequency 1 (>10 Hz) Duty cycle 0.5 (>10 Hz) Pulse width 0.
Specifications 7 Input Impedance Table 7-6 Input impedance Function Range DC Voltage[1] AC Voltage [2] AC + DC Voltage[2] Input Impedance 50.000 mV 10.00 MΩ 500.00 mV 10.00 MΩ 1000.0 mV 10.00 MΩ 5.0000 V 11.10 MΩ 50.000 V 10.10 MΩ 500.00 V 10.01 MΩ 1000.0 V 10.001 MΩ 50.000 mV 10.00 MΩ 500.00 mV 10.00 MΩ 1000.0 mV 10.00 MΩ 5.0000 V 10.00 MΩ 50.000 V 10.00 MΩ 500.00 V 10.00 MΩ 1000.0 V 10.00 MΩ 50.000 mV 10.00 MΩ 500.00 mV 10.00 MΩ 1000.0 mV 10.00 MΩ 5.0000 V 11.
7 Specifications General Specifications Display • Both primary and secondary displays are 5-digit liquid crystal display (LCD) with maximum reading of 50,000 counts. Automatic polarity indication.
Specifications 7 Warranty • 3 years for main unit • 3 months for standard accessories unless otherwise specified Agilent U1251B/U1252B User’s and Service Guide 155
7 156 Specifications Agilent U1251B/U1252B User’s and Service Guide
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