Hart Scientific 1504 Thermometer Readout User’s Guide Rev.
Limited Warranty & Limitation of Liability Each product from Fluke's Hart Scientific Division ("Hart") is warranted to be free from defects in material and workmanship under normal use and service. The warranty period is three years for the Thermometer Readout. The warranty period begins on the date of the shipment. Parts, product repairs, and services are warranted for 90 days.
Table of Contents 1 Before You Start . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 1.2 Symbols Used . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Safety Information . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.2.1 1.2.2 1.3 Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Cautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Authorized Service Centers. . . . . . . . . . . . . . . . . . . . . .
7.1 Serial Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 7.1.1 7.1.2 7.1.3 7.1.4 7.2 Setting the Baud Rate . . . . . . . . . . . . Automatic Transmission of Measurements . Time Stamp and System Clock . . . . . . . Duplex Mode and Linefeed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 26 26 27 GPIB Interface . . . . . . . . . . . . . . . . . . . . . . . . .
Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Connecting a four-wire probe . 12 V DC power source polarity 1504 Front Panel . . . . . . . . 1504 Back Panel . . . . . . . . Parameter Menu Structure . . . Serial Cable Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tables Table1 Table 2 Table 3 Table 4 Table 5 Table 5 iv International Electrical Symbols . . . . . . . . . . . . . . . . . . . . . 1 Typical Values for Thermistor Coefficients . . . . . . . . . . . . . . . 20 Setting Coefficients a, b, and c . . . . . . . . . . . . . . . . . . . . . . 21 Setting Coefficients a, b, c, and d . . . . . . . . . . . . . . . . . . . . 21 Command List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Command List Continued . . . . . . . . . . . . . . . . . . . . .
1 Before You Start Symbols Used 1 1.1 Before You Start Symbols Used Table 1 lists the symbols that may be used on the instrument or in this manual Table1 International Electrical Symbols and the meaning of each symbol.
1504 Thermometer Readout User’s Guide Symbol Description On Canadian Standards Association OVERVOLTAGE (Installation) CATEGORY II, Pollution Degree 2 per IEC1010-1 refers to the level of Impulse Withstand Voltage protection provided. Equipment of OVERVOLTAGE CATEGORY II is energy-consuming equipment to be supplied from the fixed installation. Examples include household, office, and laboratory appliances.
1 Before You Start Safety Information Before initial use, or after transport, or after storage in humid or semi-humid environments, or anytime the instrument has not been energized for more than 10 days, the instrument needs to be energized for a “dry-out” period of 2 hours before it can be assumed to meet all of the safety requirements of the IEC 1010-1.
1504 Thermometer Readout User’s Guide 1.2.2 Cautions To avoid possible damage to the instrument, follow these guidelines. DO NOT change the values of the calibration constants from the factory set values unless you are recalibrating the instrument. The correct setting of these parameters is important to the safety and proper operation of the instrument. Allow sufficient air circulation by leaving at least 3 inches of space between the thermometer and nearby objects.
1 Before You Start Authorized Service Centers Phone: +1.801.763.1600 Telefax: +1.801.763.1010 E-mail: support@hartscientific.com Fluke Nederland B.V. Customer Support Services Science Park Eindhoven 5108 5692 EC Son NETHERLANDS Phone: +31-402-675300 Telefax: +31-402-675321 E-mail: ServiceDesk@fluke.
1504 Thermometer Readout User’s Guide When contacting these Service Centers for support, please have the following information available: • Model Number • Serial Number • Voltage • Complete description of the problem 6
2 Introduction 2 Introduction The 1504 Thermometer Readout is a low-cost high-accuracy digital thermometer readout designed to be used with thermistors or RTDs with a nominal resistance of 1,000Ω or greater. Its unique combination of features makes it suitable for a wide variety of applications from laboratory measurement to industrial processes. Features of the 1504 include: • Measures with most any thermistor • Four-wire connection eliminates lead resistance effects • Accuracy: 0.
3 Specifications and Environmental Conditions Specifications 3 3.1 Specifications and Environmental Conditions Specifications Resistance range 0 to 1 MΩ, auto-ranging Resistance accuracy, one year 1 0 to 5 kΩ: 0.5Ω 5 kΩ to 200 kΩ: 0.01% (100 ppm) of reading 200 kΩ to 1 MΩ: 0.03% (300 ppm) of reading Resistance accuracy, short term 1 0 to 5 kΩ: 0.25Ω 5 kΩ to 200 kΩ: 0.005% (50 ppm) of reading 200 kΩ to 1 MΩ: 0.02% (200 ppm) of reading Temperature accuracy, typical1, 3, 4 0°C: 0.002°C 25°C: 0.
04 Thermometer Readout User’s Guide Communications RS-232 serial standard, IEEE-488 (GPIB) optional, Conforms to IEEE-488.1, Capability: AH1, SH1, T6, L4, DC1 Operating Temperature Range Full accuracy: 13°C to 33°C Absolute: 0°C to 55°C AC Power 115 VAC (±10%), 50/60 Hz, 10 W, nominal 1 A maximum 230 VAC (±10%), 50/60 Hz, 10 W (optional) Detachable power cord DC Power (optional) 10–14 VDC (±10%), 1 A maximum (220 mA typical, normal mode; 120 mA typical, power saver mode) Size 5.6 in. (14.
4 Quick Start Unpacking 4 Quick Start This section briefly explains the basics of setting up and operating your 1504 thermometer readout. 4.1 Unpacking Unpack the thermometer carefully and inspect it for any damage that may have occurred during shipment. If there is shipping damage, notify the carrier immediately.
1504 Thermometer Readout User’s Guide to pins 4 and 5. (Pins 1 and 5 source current and pins 2 and 4 sense the potential.) If a shield wire is present it should be connected to pin 3. Probe Connector 1 5 2 3 4 Shield RTD Sensor Figure 1 Connecting a four-wire probe A two-wire probe can also be used with the 1504. It is connected by attaching one wire to both pins 1 and 2 of the plug and the other wire to both pins 4 and 5. If a shield wire is present it should be connected to pin 3.
4 Quick Start DC Power Option ductor is positive and the inside is negative. When operating in DC mode, the AC power switch on the rear panel is not functional. – + Figure 2 12 V DC power source polarity The optional 9313 Battery Pack, available from Hart Scientific, can be used as a portable power source for the 1504. It includes a 1.2 amp-hr 12V sealed lead-acid battery, a DC power cord that plugs into the 1504’s DC input, a carrying bag, and a battery charger.
1504 Thermometer Readout User’s Guide NOTE: The DC power option includes a low voltage indicator. The low voltage indicator needs to be plugged into the instrument with the battery option plugged in to the low voltage indicator. The low voltage indicator light illuminates when the voltage drops below a safe operating range. The instrument should not be used for measuring when the low voltage light is illuminated. Recharge the battery to an acceptable level before taking measurements.
5 Parts and Controls Front Panel Buttons 5 5.1 Parts and Controls Front Panel Buttons See Figure 3. The front panel buttons are used to select units of measurement, access operating parameters, and alter operating parameters. The function of each button is as follows: C/Probe—This button selects units of degrees Celsius. In conjunction with the Menu button, it selects the probe parameter menu. F/Sample—This button selects units of degrees Fahrenheit.
1504 Thermometer Readout User’s Guide 5.2 Rear Panel See Figure 4. Serial Port - The DB-9 connector is for interfacing the thermometer to a computer or terminal with serial RS-232 communications. Probe Connector - At the rear of the thermometer is the probe connector. The probe must be connected for operation. Power Switch - The power switch is located on the rear of the thermometer. The AC power switch turns the unit on and off. It does not control the DC power.
6 General Operation Selecting Units 6 General Operation This section explains basic operation of the 1504 Thermometer. 6.1 Selecting Units Temperature can be displayed in degrees Celsius (indicated with “C”), degrees Fahrenheit (indicated with “F”), or Kelvin (indicated with “A” for absolute). The resistance of the sensor can also be displayed (indicated with “o” for ohms). Simply press the appropriate unit button, C, F, K, or Ω to select the units. 6.
1504 Thermometer Readout User’s Guide Menu Probe Sample Comm (Cal) Set probe type Set filter Set clock Enter password Pr= thr FI= 4 11.23.30 PA= 0000 Set coefficients Set power saver Set time stamp Set menu lockout PS= OFF ts= OFF LO=CaL Set baud rate Set CAL0 2400 b -000.06 Test conversion Set sample period Set CAL 100 1.000000 00.00.01 +001.28 Set duplex Set CAL 400 duP=FULL -0001.
6 General Operation Selecting the Probe Characterization when all the digits are correct. If the password is entered correctly the first parameter in the menu will appear. 6.4 Selecting the Probe Characterization Before the 1504 can measure temperature accurately it must know how to calculate temperature from the resistance of the sensor. You must enter the proper characterization coefficients. The coefficients are determined when the probe is calibrated.
1504 Thermometer Readout User’s Guide E -04 Increase or decrease the exponent using the U and D buttons. Once the exponent is correct, press Enter to store it. 6.4.3 Steinhart-Hart Characterization Thermistors are most often characterized using the Steinhart-Hart equation: r( T [ K ])[ Ω ] = exp[ Bo + B1 T −1 + B2 T −2 + B3 T −3 ] This is the default probe type. The parameters that appear for this option are “b0”, “b1”, “b2”, and “b3”.
6 General Operation Selecting the Probe Characterization b=4.6354171E03, c=-1.2531030E05, and d=-6.2365913E06. Set the 1504 parameters with values from the certificate as follows. Table 4 Setting Coefficients a, b, c, and d 1504 Coefficient Certificate Value b0 a b1 b b2 c b3 d Example 2: A thermistor’s calibration certificate gives coefficients a=-4.2501569E00, b=3.8997001E03, and c=-1.4225654E07. Set the 1504 parameters with values from the certificate as follows.
1504 Thermometer Readout User’s Guide ⎧R0 (1 + At + B 2 ) r( t[ °C ] ) = ⎨ 2 3 ⎪⎩R0 1 + At + Bt + C (t − 100)t [ ] t≥0 t<0 The A, B, and C coefficients can be converted to α, δ, and β coefficients using the following formulas: α = A + 100 B 6.4.5 δ=− 100 A +1 100 B β=− 10 8 C A + 100 B Testing the coefficients The 1504 provides a convenient method for testing the coefficients you have entered to make sure they have been entered correctly.
6 General Operation Power Saver play as an indication that the 1504 is still operating. Pressing any button on the front panel restores the display. You can program the power saver to activate after a specified period of time from 5 minutes to 60 minutes in intervals of 5 minutes. You can also disable the power saver feature completely. The power saver is off by default. The power saver is programmed in the Sample menu. Press the Menu button (“SEt?” appears) then press the Sample menu button.
7 Digital Communications Interface Serial Interface 7 Digital Communications Interface Remote communications allows an external device, such as a computer, to communicate with the 1504 to obtain measurement data and control its operation. Communication is accomplished with various commands issued to the 1504 through the RS-232 port or optional IEEE-488 port. A full list of commands is given in Section7.3. 7.1 Serial Interface The 1504 is equipped with an RS-232 serial port.
1504 Thermometer Readout User’s Guide 7.1.2 Automatic Transmission of Measurements The 1504 can be programmed to automatically send measurements to a remote printer or terminal. The transmission interval is set using the “SA PEr” sample period parameter. This is set in the Comm menu after the baud rate parameter. The display will briefly indicate “SA PEr” and then display the current sample period. The sample period is specified in hours, minutes, and seconds.
7 Digital Communications Interface GPIB Interface to the time stamp parameter. The display will briefly show “ti Sta” then the time stamp state which is either ON or OFF. Use the U and D buttons to change the state and press Enter. ON enables transmission of the time stamp and OFF disables it. The time stamp can also be set using the “ST” communications command. The command ST=ON enables the time stamp and ST=OF disables it.
1504 Thermometer Readout User’s Guide 7.2.1 Setting the Address The IEEE-488 bus requires that each device has a unique address. The default address of the 1504 is 22 but can be changed if necessary. The IEEE-488 address of the 1504 is set within the Comm menu after the serial linefeed parameter. (This menu option will not appear if the IEEE-488 interface is not installed). Press the Menu button (“SEt?” appears) then press the Comm button.
7 Digital Communications Interface Remote Commands Table 5 Command List Command Description Measurement Commands T read measurement (includes label, unit, and time) F[ETCH?] read measurement value (SCPI compatible) SA[=[[[hh:]mm:]ss] read [or set] serial sample period U=C|F|K|O select units ST[=ON/OF] read [or set] the time stamp CL[=hh:mm:ss] read [or set] the system clock Probe Characterization Commands PR[=T/R|R|] read [or select] the characterization type R0[=] read [or set] R0
1504 Thermometer Readout User’s Guide Command List Continued *VER read model number and firmware version number IDN? read manufacturer, model number, serial number, and firmware version number (SCPI compatible) H read a partial list of commands 7.3.1.1 Reading Temperature The most recent temperature measurement can be read using the following command: T reads the most recent measurement The syntax of the response is as follows: t:_nnnn.nnn_u or t:_nnnn.
7 Digital Communications Interface Remote Commands SA=5:00 sets the sample period to 5 minutes SA=1:00:00 sets the sample period to 1 hour 7.3.1.3 Selecting the Unit of Measurement The selected unit is used in displaying measurements on the front panel and in reading measurements from the communications interfaces. The following commands can be used to select the unit of measurement: U=C selects Celsius U=F selects Fahrenheit U=K selects Kelvin U=O selects ohms 7.3.1.
1504 Thermometer Readout User’s Guide Bn= sets b0, b1, b2, or b3 for the thermistor characterization. n is a number from 0 to 3. 7.3.2.2 Testing the Characterization The following command can be used to test the probe characterization: CO= returns a temperature calculated from resistance The 1504 will respond with a temperature value computed from the given resistance value. The temperature is given in the currently selected unit.
7 Digital Communications Interface Remote Commands 7.3.4.1 Setting the Duplex Mode When the RS-232 duplex mode is set to FULL all commands received by the 1504 from the RS-232 port are echoed back. Setting the mode to HALF disables the echo. The duplex mode can be set remotely using the commands: DU=F sets duplex to full DU=H sets duplex to half 7.3.4.
1504 Thermometer Readout User’s Guide 7.3.5.4 Setting the Serial Number The following command is used to set the serial number of the 1504: *SN= sets the instrument’s serial number 7.3.6 Other Commands Remaining commands are described below. 7.3.6.1 Instrument Identification The following command returns the model number and firmware version number: *VER returns the model and firmware version numbers The syntax of the response is as follows: ver.mmmm,v.
8 Calibration Procedure Accessing the Calibration Parameters 8 Calibration Procedure The 1504 uses a three-point calibration scheme with a quadratic polynomial correction function to maintain the accuracy of its resistance measurement. The three calibration points are at 0Ω, 10 kΩ, and 100 kΩ. Three calibration parameters determine the correction function: CAL0, CAL10, and CAL100. The CAL0 parameter sets the correction at 0Ω resistance (but does not affect the correction at 10 kΩ).
1504 Thermometer Readout User’s Guide 8.2 Calibration Procedure Calibration requires four-wire 10 kΩ and 100 kΩ resistors of 25 ppm uncertainty and a 0Ω resistor (or short). For verification, 4 kΩ and 40 kΩ resistors of 25 ppm uncertainty, and a 1 MΩ resistor of 75 ppm uncertainty are also required. The resistors are connected to the input the same way probes are. The calibration procedure is as follows: 36 1. Connect a 0Ω resistor to the input and measure its resistance.
9 Maintenance 9 Maintenance • The calibration instrument has been designed with the utmost care. Ease of operation and simplicity of maintenance have been a central theme in the product development. Therefore, with proper care the instrument should require very little maintenance. Avoid operating the instrument in an oily, wet, dirty, or dusty environments. • If the outside of the instrument becomes soiled, it may be wiped clean with a damp cloth and mild detergent.
10 Troubleshooting 10 Troubleshooting In case you run into difficulty while operating the 1504, this section provides some suggestions that may help you solve the problem. Below are several situations that may arise followed by possible causes of the problem and suggested actions you might take. Incorrect Temperature Reading While attempting to measure temperature the display shows an incorrect value.
1504 Thermometer Readout User’s Guide • Stem conduction error. The problem may be that the actual temperature of the sensor is not what you expect. This is often the result of stem conduction where heat flowing through the stem of the probe to ambient affects the temperature of the probe. It is very important that immersion probes be inserted to an adequately depth into the material being measured.
10 Troubleshooting CE Comments 10.1.1.1 Immunity Testing The instrument was tested to the requirements for industrial locations. This allows the instrument to be used in all types of locations from the laboratory to the factory floor. Criterion C was used for Electrostatic Discharge (ESD, IEC 61000-4-2) and Electric Fast Transit (EFT, Burst, IEC 61000-4-4). If the instrument is subjected to EFT conditions at 2kV, the instrument may require the user to cycle the power to return to normal operation. 10.1.
