® 27 II/28 II Digital Multimeters Users Manual September 2009, Rev. 1, 10/10 © 2009, 2010 Fluke Corporation. All rights reserved. Specifications are subject to change without notice. All product names are trademarks of their respective companies.
Lifetime Limited Warranty Each Fluke 20, 70, 80, 170, 180 and 280 Series DMM will be free from defects in material and workmanship for its lifetime. As used herein, “lifetime” is defined as seven years after Fluke discontinues manufacturing the product, but the warranty period shall be at least ten years from the date of purchase.
Table of Contents Title Page Introduction .................................................................................................................... How to Contact Fluke ..................................................................................................... Safety Information .......................................................................................................... Features ............................................................................................
27 II/28 II Users Manual Capacitance Measurements ..................................................................................... Diode Tests............................................................................................................... AC or DC Current Measurements ............................................................................. Frequency Measurements ........................................................................................ Duty Cycle Measurements .........
Contents (continued) Diode ......................................................................................................................... Frequency ................................................................................................................. Frequency Counter Sensitivity and Trigger Levels .................................................... Duty Cycle (Vdc and mVdc) ...................................................................................... Input Characteristics...
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List of Tables Table 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. Title Page Symbols................................................................................................................................. Inputs .................................................................................................................................... Rotary Switch Positions......................................................................................................... Pushbuttons ...........................
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List of Figures Figure 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. Title Page Display Features ................................................................................................................... AC and DC Voltage Measurements ...................................................................................... Low-Pass Filter...................................................................................................................... Continuity Tests..................................
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Introduction How to Contact Fluke XW Warning Read “Safety Information” before using the Meter. Except where noted, the descriptions and instructions in this manual refer to both Series II Models 27 and 28 multimeters (hereafter referred to as “the Meter”). Model 28 II appears in all illustrations. The Model 27 II is an average-responding Digital Multimeter while the 28 II is a True-rms Digital Multimeter. In addition the 28 II measures temperature using a type-K thermocouple.
27 II/28 II Users Manual Safety Information XWWarning The Meter complies with: To avoid possible electric shock or personal injury, follow these guidelines: • • • • ISA-82.02.01 CAN/CSA-C22.2 No. 61010-1-04 IEC Standard No. 61010-1:2001 Measurement Category III, 1000V, Pollution Degree 2 • Measurement Category IV, 600V, Pollution Degree 2 In this manual, a Warning identifies conditions and actions that pose hazards to the user.
Digital Multimeters Safety Information • • Inspect the test leads for damaged insulation or exposed metal. Check the test leads for continuity. Replace damaged test leads before you use the Meter. Do not apply more than the rated voltage, as marked on the Meter, between the terminals or between any terminal and earth ground. • Never operate the Meter with the cover removed or the case open. • Use caution when working with voltages above 30 V ac rms, 42 V ac peak, or 60 V dc.
27 II/28 II Users Manual • When servicing the Meter, use only specified replacement parts. • This multimeter is not to be used to check electrical blasting circuits. • When using probes, keep fingers behind the finger guards on the probes. • • Do not use the Low-Pass Filter to verify the presence of hazardous voltages. Voltages greater than what is indicated may be present. First, make a voltage measurement without the filter to detect the possible presence of hazardous voltage. Then add the filter.
Digital Multimeters Safety Information Table 1. Symbols B AC (Alternating Current) F DC (Direct Current) I Fuse X Hazardous voltage P Conforms to European Union directives. W Risk of Danger. Important information. See Manual. ) Conforms to relevant Canadian Standards Association directives. Battery. Low battery when displayed. T Double insulated Continuity test or continuity beeper tone.
27 II/28 II Users Manual Features Tables 2 through 5 briefly describe the features of the Meter. Table 2. Inputs gaq112.eps Terminal 6 Description A Input for 0 A to 10.00 A current (10 - 20 A overload for 30 seconds maximum), current frequency, and duty cycle measurements. Input for 0 μA to 400 mA current measurements (600 mA for 18 hrs) and current frequency and duty cycle. COM Return terminal for all measurements.
Digital Multimeters Features Table 3. Rotary Switch Positions Function Switch Position Any Position K When the Meter is turned on, the Meter model number briefly appears on the display. AC voltage measurement Press (yellow) for low-pass filter () (28 II only) L DC voltage measurement 600 mV dc voltage range Press (yellow) for temperature () (28 II only) Press for continuity test. e Resistance measurement Press (yellow) for capacitance measurement.
27 II/28 II Users Manual Table 4. Pushbuttons Button (Yellow) Switch Position 8 Function Selects capacitance Selects temperature (28 II only) Selects ac low-pass filter function (28 II only) Switches between dc and ac current Switches between dc and ac current Any switch position Switches between the ranges available for the selected function. To return to autoranging, hold the button down for 1 second. Switches between °C and °F.
Digital Multimeters Features Table 4. Pushbuttons (cont.) Button Switch Position Continuity MIN MAX recording Hz, Duty Cycle Function Turns the continuity beeper on and off Switches between Peak (250 μs) and Normal (100 ms) response times. (28 II only) Toggles the meter to trigger on positive or negative slope. Any switch position Turns the button backlight and display backlight on, makes them brighter, and turns them off. Any switch position Starts recording of minimum and maximum values.
27 II/28 II Users Manual Table 4. Pushbuttons (cont.) Button (Relative mode) 10 Switch Position Function Any switch position Stores the present reading as a reference for subsequent readings. The display is zeroed, and the stored reading is subtracted from all subsequent readings. Any switch position except diode test Press for frequency measurements. Starts the frequency counter. Press again to enter duty cycle mode.
Digital Multimeters Features Number gaq101.eps Figure 1. Display Features Table 5. Display Features Number Feature Trig± Positive or negative slope indicator for Hz/duty cycle triggering. The continuity beeper is on. Relative (REL) mode is active. Smoothing is active. Indication - Negative readings, In relative mode, this sign indicates that the present input is less than the stored reference. High voltage present at the input.
27 II/28 II Users Manual Table 5. Display Features (cont.) Number Feature Indication Low battery. XW Warning: To A, μA, mA volts, millivolts μF, nF microfarad, nanofarad nS nanosiemens % Percent. Used for duty cycle measurements. Hz, kHz AC DC Feature °C, °F 610000 mV HiRes High resolution (Hi Res) mode. HiRes=19,999 (28 II only) Auto Autorange mode.
Digital Multimeters Features Table 5. Display Features (cont.) Number -- Feature 0L Indication Overload condition is detected. Error Messages bAtt Replace the battery immediately. di'c In the capacitance function, too much electrical charge is present on the capacitor being tested. CAL Err EEPr Err 0PEn F2_ LEAd Invalid calibration data. Calibrate Meter. Automatic Power-Off The Meter automatically turns off if you do not turn the rotary switch or press a button for 30 minutes.
27 II/28 II Users Manual Table 6. Power-Up Options Button Power-Up Option Disables automatic power-off feature (Meter normally powers off in 30 minutes). (Yellow) The Meter reads “PoFF” until is released. Enables the Meter’s calibration mode and prompts for a password. The Meter reads “CAL” and enters calibration mode. See 27 II/28 II Calibration Information. Enables the Meter’s smoothing feature. The Meter reads “'---” until is released. Turns on all LCD segments.
Digital Multimeters How to Make Measurements How to Make Measurements AC Voltage The following sections describe how to make measurements with the Meter. Switch Box AC and DC Voltage Measurements Model 28 II features true-rms readings, which are accurate for distorted sine waves and other waveforms (with no dc offset) such as square waves, triangle waves, and staircase waves. V The Meter’s voltage ranges are 600.0 mV, 6.000 V, 60.00 V, 600.0 V, and 1000 V. The select the 600.
27 II/28 II Users Manual When measuring voltage, the Meter acts approximately like a 10-MΩ (10,000,000 Ω) impedance in parallel with the circuit. This loading effect can cause measurement errors in high-impedance circuits. In most cases, the error is negligible (0.1 % or less) if the circuit impedance is 10 kΩ (10,000 Ω) or less. For better accuracy when measuring the dc offset of an ac voltage, measure the ac voltage first.
Digital Multimeters How to Make Measurements XW Warning W Caution To avoid possible electric shock or personal injury, do not use the low-pass filter to verify the presence of hazardous voltages. Voltages greater than what is indicated may be present. First, make a voltage measurement without the filter to detect the possible presence of hazardous voltage. Then, select the filter. To avoid possible damage to the Meter or other equipment, remember that while the Meter is rated for -200.0 °C to +1090.
27 II/28 II Users Manual Continuity Tests WCaution To avoid possible damage to the Meter or to the equipment under test, disconnect circuit power and discharge all high-voltage capacitors before testing for continuity. The continuity test features a beeper that sounds as long as a circuit is complete. The beeper allows you to perform quick continuity tests without having to watch the display. 18 To test for continuity, set up the Meter as shown in Figure 4. Press to turn the continuity beeper on or off.
Digital Multimeters How to Make Measurements For in-circuit tests, turn circuit power off. ON (closed) OFF (open) Activates continuity beeper gaq103.eps Figure 4.
27 II/28 II Users Manual Resistance Measurements WCaution To avoid possible damage to the Meter or to the equipment under test, disconnect circuit power and discharge all high-voltage capacitors before measuring resistance. The Meter measures resistance by sending a small current through the circuit. Because this current flows through all possible paths between the probes, the resistance reading represents the total resistance of all paths between the probes. The Meter's resistance ranges are 600.0 Ω, 6.
Digital Multimeters How to Make Measurements In-Circuit Resistance Measurements Isolating a Potentiometer Circuit Power OFF 1 3 2 Disconnect 2 1 3 Isolating a Resistor Disconnect gaq106.eps Figure 5.
27 II/28 II Users Manual How to Use Conductance for High Resistance or Leakage Tests Conductance, the inverse of resistance, is the ability of a circuit to pass current. High values of conductance correspond to low values of resistance. The Meter's 60-nS range measures conductance in nanosiemens (1 nS = 0.000000001 siemens). Because such small amounts of conductance correspond to extremely high resistance, the nS range lets you determine the resistance of components up to 100,000 MΩ, 1/1 nS = 1,000 MΩ.
Digital Multimeters How to Make Measurements Capacitance Measurements WCaution To avoid possible damage to the Meter or to the equipment under test, disconnect circuit power and discharge all high-voltage capacitors before measuring capacitance. Use the dc voltage function to confirm that the capacitor is discharged. Select Capacitance The Meter's capacitance ranges are 10.00 nF, 100.0 nF, 1.000 μF, 10.00 μF, 100.0 μF, and 9999 μF. To measure capacitance, set up the Meter as shown in Figure 6.
27 II/28 II Users Manual Diode Tests WCaution To avoid possible damage to the Meter or to the equipment under test, disconnect circuit power and discharge all high-voltage capacitors before testing diodes. Use the diode test to check diodes, transistors, silicon controlled rectifiers (SCRs), and other semiconductor devices. This function tests a semiconductor junction by sending a current through the junction, then measuring the junction's voltage drop. A good silicon junction drops between 0.5 V and 0.8 V.
Digital Multimeters How to Make Measurements Reverse Bias Forward Bias Typical Reading + + Single Beep Shorted Bad Diode Open Bad Diode or gaq109.eps Figure 7.
27 II/28 II Users Manual AC or DC Current Measurements XWWarning To avoid possible electric shock or personal injury, never attempt an in-circuit current measurement where the open-circuit potential to earth is greater than 1000 V. You may damage the Meter or be injured if the fuse blows during such a measurement. WCaution To avoid possible damage to the Meter or to the equipment under test: • Check the Meter's fuses before measuring current.
Digital Multimeters How to Make Measurements Circuit Power: OFF to connect meter. ON for measurement. OFF to disconnect meter. 1 Total Current to Circuit 4 mA A 3 A 5 2 Current Through One Component 5 gaq107.eps Figure 8.
27 II/28 II Users Manual If you are using the A terminal, set the rotary switch to mA/A. If you are using the mA/μA terminal, set the rotary switch to for currents below 6000 μA (6 mA), or for currents above 6000 μA. The following are some tips for measuring current: • 4. To measure dc current, press . If the current reading is 0 and you are sure the Meter is set up correctly, test the Meter's fuses as described under "Testing the Fuses". 5. Break the circuit path to be tested.
Digital Multimeters How to Make Measurements Frequency Measurements The following are some tips for measuring frequency: The Meter measures the frequency of a voltage or current signal by counting the number of times the signal crosses a threshold level each second. • Table 7 summarizes the trigger levels and applications for measuring frequency using the various ranges of the Meter's voltage and current functions. To measure frequency, connect the Meter to the signal source; then press .
27 II/28 II Users Manual Table 7. Functions and Trigger Levels for Frequency Measurements Function Range Typical Application K 6 V, 60 V, 600 V, 1000 V ±5 % of scale Most signals. K 600 mV ±30 mV High-frequency 5 V logic signals. (The dc-coupling of the L function can attenuate high-frequency logic signals, reducing their amplitude enough to interfere with triggering.) mL L 600 mV 40 mV Refer to the measurement tips given before this table. 6V 1.7 V 5 V logic signals (TTL).
Digital Multimeters How to Make Measurements For 5-V logic signals, use the 6-V dc range. For 12-V switching signals in automobiles, use the 60 V dc range. For sine waves, use the lowest range that does not result in multiple triggering. (Normally, a distortion-free signal can be up to ten times the amplitude of the selected voltage range.) Duty Cycle Measurements Duty cycle (or duty factor) is the percentage of time a signal is above or below a trigger level during one cycle (Figure 9).
27 II/28 II Users Manual How to Determine Pulse Width For a periodic waveform (its pattern repeats at equal time intervals), you can determine the amount of time that the signal is high or low as follows: 1. Measure the signal's frequency. 2. Push a second time to measure the signal's duty cycle. Push to select a measurement of the signal's positive or negative pulse, refer to Figure 9. 3.
Digital Multimeters HiRes Mode (28 II) Zoom Mode (Power Up Option Only) To use the Rel Zoom Bargraph: 1. Hold down while turning the Meter on. The display reads “2rEL”. 2. Select the relative mode by pressing again. 3. The center of the bargraph now represents zero and the sensitivity of the bargraph increases by a factor of 10. Measured values more negative than the stored reference activate segments to the left of center; values more positive activate segments to the right of center.
27 II/28 II Users Manual MIN MAX Recording Mode The MIN MAX mode records minimum and maximum input values. When the inputs go below the recorded minimum value or above the recorded maximum value, the Meter beeps and records the new value. This mode can be used to capture intermittent readings, record maximum readings while you are away or record readings while you are operating the equipment under test and cannot watch the Meter.
Digital Multimeters Smooth Feature (Power Up Option Only) Table 8. MIN MAX Functions Button (while in MIN MAX mode) PEAK MIN MAX (hold for 1 second) MIN MAX Function Enter MIN MAX recording mode. The Meter is locked in the range displayed before you entered MIN MAX mode. (Select the desired measurement function and range before entering MIN MAX.) The Meter beeps each time a new minimum or maximum value is recorded. Step through maximum (MAX), minimum (MIN), average (AVG) and present values.
27 II/28 II Users Manual AutoHOLD Mode XWWarning To avoid possible electric shock or personal injury, do not use AutoHOLD mode to determine that circuits are without power. The AutoHOLD mode will not capture unstable or noisy readings. The AutoHOLD mode captures the present reading on the display. When a new, stable reading is detected, the Meter beeps and displays the new reading. To enter or exit AutoHOLD mode, press .
Digital Multimeters Maintenance Fuse Test Maintenance XWWarning To avoid possible electric shock or personal injury, repairs or servicing not covered in this manual should be performed only by qualified personnel as described in the 27 II/28 II Calibration Information. General Maintenance Periodically wipe the case with a damp cloth and mild detergent. Do not use abrasives or solvents. Dirt or moisture in the terminals can affect readings and can falsely activate the Input Alert feature.
27 II/28 II Users Manual How to Replace the Batteries Replace the batteries with three AA batteries (NEDA 15A IEC LR6). Good 0.44 A fuse: 0.995 kΩ to 1.005 kΩ XWWarning To avoid false readings, which could lead to possible electric shock or personal injury, replace the battery as soon as the battery indicator () appears. If the display shows “batt” the Meter will not function until the battery is replaced.
Digital Multimeters Service and Parts 4. Ensure the battery compartment gasket () is properly installed around the outside edge of the battery compartment barrier. 5. Replace the battery door by aligning the battery compartment barrier with battery compartment. 6. 7. Replace the fuse compartment door by aligning the arrow on the fuse door with the arrow on the case bottom and lowering the door into the fuse compartment. 8.
27 II/28 II Users Manual 1 3 4 2 6 5 gaq10.eps Figure 11.
Digital Multimeters Service and Parts Table 9. Replacement Parts Description Qty. Fluke Part or Model Number Battery, AA 1.5 V 3 376756 Fuse, 0.
27 II/28 II Users Manual Screw AC72 Alligator Clips Battery Door Gasket Battery Door Holster TL75 Test Lead Set Battery AA 1.5 V Fuse Access Door Fuse 11 A, 1000 V, Fast Fuse 0.440 A, 1000 V, Fast Fuse Cap 27 II/28 II Users Manual CD 27 II/28 II Getting Started Manual 80BK-A Integrated DMM Temperature Probe (28 II only) gaq111.eps Figure 12.
Digital Multimeters Service and Parts Table 10.
27 II/28 II Users Manual General Specifications Maximum voltage between any terminal and earth ground............................................ 1000 V rms W Fuse for mA inputs .................................................. 440 mA, 1000 V FAST Fuse W Fuse for A inputs ..................................................... 11 A, 1000 V FAST Fuse Display Digital ..........................................................................
Digital Multimeters General Specifications Electromagnetic Compatibility (EN 61326-1:1997).....In an RF field of 3 V/M, accuracy = specified accuracy +20 counts, except 600 μA dc range total accuracy = specified accuracy +60 counts. Temperature not specified Relative Humidity ..........................................................0 % to 95 % (0 °C to 35 °C) 0 % to 70 % (35 °C to 55 °C) Battery Type...................................................................
27 II/28 II Users Manual Detailed Specifications For all detailed specifications: Accuracy is specified for 2 years after calibration, at operating temperatures of 18 °C to 28 °C, with relative humidity at 0 % to 95 %. Accuracy specifications take the form of ±([% of Reading] + [Number of least-significant digits]). For Model 28 II in the 4 ½-digit mode, multiply the number of least-significant digits (counts) by 10. 27 II AC Voltage Range Resolution 600.0 mV 0.1 mV 6.000 V 0.001 V 60.00 V 0.
Digital Multimeters Detailed Specifications 28 II AC Voltage AC conversions are ac-coupled and valid from 3 % to 100 % of range. Range Resolution 600.0 mV 0.1 mV 6.000 V 0.001 V 60.00 V 0.01 V 600.0 V 0.1 V 1000 V 1V Accuracy 45 – 65 Hz 15 – 200 Hz 200 – 440 Hz 440 Hz – 1 kHz ±(0.7 % + 4) ±(1.0 % + 4) Low-Pass Filter ±(1.0 % + 4) [1] -6.0 % - 4 [4] [1] Below 30 Hz, use smoothing function. [2] Below 10 % of range, add 12 counts. [3] Frequency range: 1 to 2.
27 II/28 II Users Manual DC Voltage, Conductance, and Resistance Function mV dc V dc Ω nS Range Resolution 600.0 mV 0.1 mV 6.000 V 0.001 V 60.00 V 0.01 V 600.0 V 0.1 V 1000 V 1V 600.0 Ω 0.1 Ω 6.000 kΩ 0.001 kΩ 60.00 kΩ 0.01 kΩ 600.0 kΩ 0.1 kΩ 6.000 MΩ 0.001 MΩ 50.00 MΩ 0.01 MΩ 60.00 nS 0.01 nS Accuracy ±(0.1 % + 1) ±(0.05 % + 1) ±(0.2 % + 2) [2] ±(0.2 % + 1) ±(1.0 % + 1) ±(1.0 % + 10) [1] [1,2] [1] Add 0.
Digital Multimeters Detailed Specifications Temperature (28 II Only) Range Resolution -200 °C to +1090 °C -328 °F to +1994 °F [1] [2] Accuracy 0.1 °C 0.1 °F [1,2] ±(1.0 % + 10) ±(1.0 % + 18) Does not include error of the thermocouple probe. Accuracy specification assumes ambient temperature stable to ± 1 °C. For ambient temperature changes of ± 5 °C, rated accuracy applies after 2 hour. AC Current Accuracy Function μA ac mA ac A ac Range Resolution Burden Voltage 600.0 μA 0.
27 II/28 II Users Manual DC Current Function μA dc mA dc A dc [1] [2] [3] Range Resolution Burden Voltage Accuracy 27 II 28 II 600.0 μA 0.1 μA 100 μV/μA ±(0.2 % + 4) ±(0.2 % + 4) 6000 μA 1 μA 100 μV/μA ±(0.2 % + 2) ±(0.2 % + 2) 0.01 mA 1.8 mV/mA ±(0.2 % + 4) ±(0.2 % + 4) 0.1 mA 1.8 mV/mA ±(0.2 % + 2) ±(0.2 % + 2) 0.001 A 0.03 V/A ±(0.2 % + 4) ±(0.2 % + 4) 0.01 A 0.03 V/A ±(0.2 % + 2) ±(0.2 % + 2) 60.00 mA 400.0 mA [1] 6.000 A 10.
Digital Multimeters Detailed Specifications Diode Range Resolution 2.000 V Accuracy ±(1.0 % + 1) 0.001 V Frequency Range Resolution 199.99 Hz 0.01 Hz 1999.9 Hz 0.1 Hz 19.999 kHz 0.001 kHz 199.99 kHz 0.01 kHz >200 kHz 0.1 kHz [1] Accuracy ±(0.005 % + 1) [1] Unspecified From 0.5 Hz to 200 kHz and for pulse widths >2 μs. Frequency Counter Sensitivity and Trigger Levels Minimum Sensitivity (RMS Sine Wave) Input Range 5 Hz – 20 kHz 0.
27 II/28 II Users Manual Duty Cycle (Vdc and mVdc) Range 0.0 % to 99.9 % [1] Accuracy [1] Within ± (0.2 % per kHz + 0.1 %) for rise times < 1 μs. 0.5 Hz to 200 kHz, pulse width >2 μs. Pulse width range is determined by the frequency by the frequency of the signal.
Digital Multimeters Detailed Specifications MIN MAX Recording Nominal Response Accuracy 27 II 28 II Specified accuracy ±12 counts for changes 100 ms to 80 % >200 ms in duration (±40 counts in ac with beeper on) 100 ms to 80 % Specified accuracy ±12 counts for (dc functions) changes >200 ms in duration 120 ms to 80 % (ac functions) Specified accuracy ±40 counts for changes >350 ms and inputs >25 % of range Specified accuracy ±100 counts for changes >250 μs in duration 250 μs (peak) [1] (add ±100
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