Handheld Temperature Meters A M0618
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User’s Guide s & Assemblies ® http://www.omega.com e-mail: info@omega.com Only model 871A has CE certification 871A and 872A Digital Thermometers omega.com TM OMEGA® OMEGAnet SM On-Line Service http://www.omega.com Internet e-mail info@omega.com Servicing North America: USA: ISO 9001 Certified Canada: One Omega Drive, Box 4047 Stamford, CT 06907-0047 Tel: (203) 359-1660 e-mail: info@omega.com 976 Bergar Laval (Quebec) H7L 5A1 Tel: (514) 856-6928 e-mail: canada@omega.com FAX: (203) 359-7700 FAX: (514) 856-6886 For immediate technical or application assistance: USA and Canada: Mexico and Latin America: Sales Service: 1-800-826-6342 / 1-800-TC-OMEGASM Customer Service: 1-800-622-2378 / 1-800-622-BESTSM Engineering Service: 1-800-872-9436 / 1-800-USA-WHENSM TELEX: 996404 EASYLINK: 62968934 CABLE: OMEGA Tel: (95) 800-TC-OMEGASM En Español: (203) 359-1660 ext: 2203 FAX: (95) 203-359-7807 e-mail: espanol@omega.com Servicing Europe: Benelux: Postbus 8034, 1180 LA Amstelveen, The Netherlands Tel: (31) 20 6418405 FAX: (31) 20 6434643 Toll Free in Benelux: 06 0993344 e-mail: nl@omega.com Czech Republic: Ostravska 767, 733 01 Karvina Tel: 42 (69) 6311899 e-mail: czech@omega.com France: 9, rue Denis Papin, 78190 Trappes Tel: (33) 130-621-400 Toll Free in France: 0800-4-06342 e-mail: france@omega.com Germany/Austria: Daimlerstrasse 26, D-75392 Deckenpfronn, Germany Tel: 49 (07056) 3017 FAX: 49 (07056) 8540 Toll Free in Germany: 0130 11 21 66 e-mail: germany@omega.com United Kingdom: 25 Swannington Road, P.O. Box 7, Omega Drive, Broughton Astley, Leicestershire, Irlam, Manchester, LE9 6TU, England M44 5EX, England Tel: 44 (1455) 285520 Tel: 44 (161) 777-6611 FAX: 44 (1455) 283912 FAX: 44 (161) 777-6622 Toll Free in England: 0800-488-488 e-mail: uk@omega.com ISO 9002 Certified FAX: 42 (69) 6311114 FAX: (33) 130-699-120 It is the policy of OMEGA to comply with all worldwide safety and EMC/EMI regulations that apply. OMEGA is constantly pursuing certification of its products to the European New Approach Directives. OMEGA will add the CE mark to every appropriate device upon certification. The information contained in this document is believed to be correct but OMEGA Engineering, Inc. accepts no liability for any errors it contains, and reserves the right to alter specifications without notice. WARNING: These products are not designed for use in, and should not be used for, patient connected applications. TABLE OF CONTENTS MODEL 871A AND MODEL 872A DIGITAL THERMOMETERS SECTION PAGE SECTION 1 INTRODUCTION .................................................................. 1 1.1 1.2 2.1 General Description ................................................................... 1 Features ..................................................................................... 1 Accessory Items......................................................................... 1 SECTION 2 INSTALLATION .................................................................... 2 2.1 2.2 Unpacking.................................................................................. 2 Battery Installation ..................................................................... 2 SECTION 3 OPERATION ......................................................................... 3 3.1 3.2 Controls and Indicators.............................................................. 3 Operating Procedure.................................................................. 5 SECTION 4 SERVICE INFORMATION .................................................... 5 4.1 4.1.1 4.1.2 4.2 4.2.1 4.2.2 4.2.3 4.2.4 4.3 4.3.1 4.3.2 4.3.3 4.3.4 4.4 4.5 4.5.1 4.5.2 4.5.3 4.5.4 Verification Check ...................................................................... 5 Functionality Check ................................................................... 5 Accuracy Check......................................................................... 6 Calibration for Model 871A ........................................................ 6 Equipment Needed .................................................................... 6 Environmental Conditions.......................................................... 6 Setup.......................................................................................... 7 Calibration Procedure ................................................................ 7 Calibration for Model 872A ........................................................ 8 Equipment Needed .................................................................... 8 Environmental Conditions.......................................................... 8 Setup.......................................................................................... 8 Calibration Procedure ................................................................ 9 Disassembly for Model 871A and Model 872A.........................10 Troubleshooting Guide .............................................................11 DC Voltage checks Model 871A ...............................................12 DC Voltage Checks Model 872A ..............................................12 Waveform Checks Model 871A ................................................13 Waveform Checks Model 872A ................................................13 SECTION 5 5.1 SPECIFICATIONS FOR MODEL 871A AND MODEL 872A .............................................................13 Parts List ...................................................................................16 i SECTION 1.1 1 INTRODUCTION GENERAL DESCRIPTION The OMEGA® Model 871A and Model 872A Digital Thermometers are ultrasensitive hand held instruments. Low power LSI devices combined with a large 0.6" (15 mm) LCD, deliver reliability, extended battery life, and an extremely readable readout. One nine volt battery will deliver 100 hours of continuous operation. The 871A and 872A are operationally identical except for minor differences related to each model’s thermocouple input: Model 871A is designed for use with type K (Chromel-Alumel) thermocouples; Model 872A is designed for use with type J (Iron-Constantan) thermocouples. Cold junction electronic circuitry in the Model 871A and Model 872A automatically compensates for ambient temperature changes. A special integrating A/D converter corrects for thermocouple non-linearity during each digitization cycle. The resulting conformity to the standard thermocouple voltage table is within 1ºC over the entire measurement span of the instrument. Although the 871A and 872A are ideal for temperature measurement in the field, they also function well as bench instruments when equipped with the optional tilt stand. The Model 871A and Model 872A provide dual inputs, selectable scales (ºF/ºC), 1.0º and 0.1º resolution, and an analog output. The versatile dual input configuration permits two point temperature measurement such as those required in process monitoring. The analog output allows interfacing with chart recorders or data acquisition system’s functioning as an electronic ice-point reference. 1.2 FEATURES • Wide temperature range • Selectable scales (ºF/ºC) • 0.1º and 1.0º resolution • 0.25% accuracy 1.2.1 • Dual thermocouple inputs • Analog output • Heavy duty construction ACCESSORY ITEMS SC-GG-[*]-30-36-SMP-M KS-871 SC-800 880-A2 U9VL SMP-[*]-M SMP-[*]-F OS-201-1 Thermocouple sensor (supplied with unit) if purchased separately. Tilt stand Soft carrying case Deluxe carrying case 9 V lithium battery Subminiature thermocouple connector, male Subminiature thermocouple connector, female 2 oz. jar of high thermal conductivity paste for fast surface measurements *Insert thermocouple type: J for Model 872, K for Model 871 1 SECTION 2.1 2 INSTALLATION UNPACKING Remove the Packing List and verify that all equipment has been received. If there are any questions about the shipment, please call OMEGA Customer Service Department at 800-622-2378 or (203) 359-1660. The following items are included: Quantity 1 2 1 1 1 Description 871 or 872 Digital Thermometer Beaded Wire Thermocouples TAS Transition Adapter 9 Volt Alkaline Battery Operator’s Manual Upon receipt of shipment, inspect the container and equipment for any sign of damage. Take particular note of any evidence of rough handling in transit. Immediately report any damage to the shipping agent. NOTE The carrier will not honor any claims unless all shipping material is saved for their examination. After examining and removing contents, save packing material and carton in the event reshipment is necessary. 2.2 BATTERY INSTALLATION WARNING Turn the model 871/872A off and disconnect the input probes before replacing the battery. Put the cover back into place on the battery compartment before resuming use of the instrument. A 9 V battery is supplied with the instrument but not installed. To install the battery, remove the cover from the battery compartment by sliding it off in the direction of the arrow located on the battery cover. The battery connector snaps on and off the terminals of the battery. Improper installation of the battery will cause the connecting wires to be severed by excess strain. Proper installation requires that the battery be positioned in such a manner (see Figure 2-1) that the leads protruding from the boot of the battery connector face toward the outside of the battery compartment. If the instrument is going to be stored for a long period of time or in a high temperature environment, remove the battery to prevent damage due to leakage. 2 Figure 2-1. Battery Installation SECTION 3 OPERATION The Model 871A is designed to work with any type K thermocouple probe or sensor, fitted with an OMEGA miniature thermocouple connector SMP-K-M or industry equivalent. The Model 872A is designed to work with any type J thermocouple probe or sensor, fitted with an OMEGA miniature connector SMP-J-M or industry equivalent. 3.1 CONTROL AND INDICATORS Figure 3-1 and Table 3-1 illustrate and describe the controls and indicators on the 871A and 872A. Figure 3-1. Model 871A Controls and Indicators *Model 872A has same controls and indicators, only range selections differ. 3 TABLE 3-1 MODEL 871A AND MODEL 872A CONTROLS AND INDICATORS ITEM CONTROL/INDICATOR FUNCTION 1. ON/OFF switch Turns unit on or off. 2. Scale and range selector Allows user to select: ºF or ºC scale, any of four possible thermocouple ranges, and 1.0º or 0.1º resolution. 3. Thermocouple selector Allows user to read either of two thermocouples by simply turning the dial. 4. Thermocouple input jacks Allows direct connection of two thermocouples to the unit via an OMEGA miniature male connector. 5. Analog output jack, +mV OUT and -mV OUT The analog output is a nonlinearized, cold junction compensated, amplified thermocouple output. (Not isolated from selected TC input.) Use a recorder to monitor temperature or a sensitive DMM to make higher resolution reading. Refer to mV output specifications for mV output to temperature ratios. 6. Low battery indicator When the battery level is low, BAT will appear in upper left corner of the display. Battery should then be replaced to avoid error erroneous readings due to battery failure. 7. Overrange/open thermocouple indication When an overrange indication or open thermocouple condition exits, a 1 followed by blanked digits will appear in the display. 4 3.2 OPERATING PROCEDURE 1. 2. 3. 4. 5. Turn power on. Select scale and range (see Tables 3-2 and 3-3). Select thermocouple TC1 or TC2. Connect one or two thermocouples to the input jacks. Connect a recorder to the analog output to monitor temperatures, or connect DMM to make high resolution readings, if desired. TABLE 3-2 MODEL 871A TEMPERATURE RANGE Range Span 200°F 2000°F 200°C 1370°C -40.0° -40° -40.0° -40° to 199.9°F to 1999°F to 199.9°C to 1370°C Resolution 0.1°F 1°F 0.1°C 1°C TABLE 3-3 MODEL 872A TEMPERATURE RANGE Range SECTION Span 200°F 1400°F 200°C 760°C -40.0° -40° -40.0° -40° 4 SERVICE INFORMATION 4.1 VERIFICATION CHECK 4.1.1 Functionality Check to 199.9°F to 1400°F to 199.9°C to 760°C Resolution 0.1°F 1°F 0.1°C 1°C Attach the GG-TC-K-24-36-SMP beaded wire thermocouple probe (supplied) to the Model 871A and the GG-TC-J-24-36-SMP beaded wire thermocouple probe (supplied) to the Model 872A. Hold the sensor end between two fingers. The reading should change from ambient to between 77º to 104º F (25º to 40ºC). 5 4.1.2 Accuracy Check 1. Prepare a pure-water ice bath (see paragraph 4.2.3, step 5). 2. Connect a thermocouple probe to input 1 of the unit. 3. Immerse the probe into the pure-water ice bath and allow ten minutes for thermal stabilization. 4. Turn on the instrument and use Tables 4-1 and 4-2 to verify that the readings on each range are within specification. TABLE 4-1 MODEL 871A RANGE CHART Range Allowable Reading 2000°F 200°F 1370°C 200°C 32° 32.0° 0° 0.0° ± ± ± ± 2° 1.8° 1° 1.0° TABLE 4-2 MODEL 872A RANGE CHART Range Allowable Reading 1400°F 200°F 760°C 200°C 32° 32.0° 0° 0.0° 4.2 CALIBRATION FOR MODEL 871A 4.2.1 Equipment Needed ± ± ± ± 2° 1.8° 1° 1.0° 1. DC Voltage Calibrator with 1 ±0.01% of setting ± 20 µV accuracy. 2. 100: 1 divider: 1.98 kilohm and 20 ohm wirewound resistors with 0.02% ratio accuracy or better. 3. OMEGA TRC III Ice Point Reference Chamber or distilled water ice bath. 4. OMEGA type K TRP Reference Probe or make a thermocouple transition junction (see paragraph 4.2.3). 4.2.2 Environmental Conditions To meet all specifications, the conditions for calibration should be an ambient temperature 23º ± 1ºC; relative humidity less than 80%. 6 4.2.3 Setup (Refer to Figure 4-1.) 1. To make a thermocouple transition junction, silver solder a piece of copper wire to each (type K) thermocouple wire and insulate the junction with a waterproof jacket. 2. Connect the thermocouple wires from the type K transition junction to an OMEGA miniature thermocouple connector SMP-K-M. 3. Plug in the miniature connector to input TC1 of the Model 871A. 4. Connect the copper wires to the 100:1 divider (see Figure 4-1) with the copper/wire (positive) junction connected through the 1.98 kilohm resistor, to the dc calibrator positive terminal. 5. Prepare a distilled water ice bath as follows: a. Drill a hole in the cap of a Dewar flask or ThermosTM to accommodate the transition junction. b. Firmly pack the flask with pea-size ice chips made from distilled water and then fill the flask with distilled water.* c. Replace the melted ice with more ice while removing excess water. d. Place cap on the flask and insert the transition junction into the flask. Allow 20 minutes for temperature stabilization. *Using tap water may cause inaccuracies due to contaminants. *The 20Ω resistor must be held at a uniform temperature during calibration. Figure 4-1. Calibration Setup for Model 871A 4.2.4 Calibration Procedure It is not necessary to disassemble the case for calibration. All adjustments are accessible by removing the covers shown in Figure 4-2. 1. Remove the battery and trimmer compartment covers from the Model 871A. 2. Turn the Model 871A on and perform the calibration adjustments listed in Table 4-3. 7 Figure 4-2. Access to Calibration Adjustments TABLE 4-3 CALIBRATION ADJUSTMENTS FOR MODEL 871A Step 1 2 3 4 5 Adjustment Input Offset Null + Gain (X1) + Gain (X10) - Gain ºF Offset 871 Range 220ºC 1370ºC 200ºC 200ºC 200ºF 4.3 CALIBRATION FOR MODEL 872A 4.3.1 Equipment Needed Calibrator Setting (V) 0.0000 5.3039 0.6939 -0.1527 0.000 Trimmer Adjust R109 R104 R105 R103 R102 Desired Reading 00.0ºC 1320ºC 170.0ºC -40.0ºC 32.0ºF 1. DC voltage calibrator with ±0.01% of setting and ± 20 µV accuracy. 2. 100: 1 divider: 1.98 kilohm and 20 ohm wirewound resistors with 0.02% ratio accuracy or better. 3. OMEGA TRC III Ice Point Reference Chamber or distilled water ice bath. 4. OMEGA type J TRP Reference Probe or make a thermocouple transition junction (see paragraph 4.3.3). 4.3.2 Environmental Conditions To meet all specifications, the conditions for calibration should be: an ambient temperature of 23º ± 1ºC; relative humidity less than 80%. 4.3.3 Setup 1. To make a thermocouple transition junction, silver solder a piece of copper wire to each (type J) thermocouple wire and insulate the junction with a waterproof jacket. 2. Connect the thermocouple wires from the type J transition junction to an OMEGA miniature connector SMP-J-M. 8 4.5.1 3. Plug in the miniature connector to input TC1 of the Model 872A. 1. Battery: VBAT > 7 V 2. Power Supplies: V + to (Analog Ground) = +2.8 ± 0.4 V V + to (Digital Ground) = +5 ± 1 V 3. Reference Diode: CR101 to (Analog Ground) = -1.23 ± 0.03 V 4. Negative Reference Divider: (Reference to Analog Ground) 4. Connect the copper wires to the 100:1 divider (see Figure 4-3) with the iron wire connected through the 1.98 kilohm resistor, to the dc calibrator positive terminal. ➱➡ DC Voltage Checks For Model 871A ➱ 5. Prepare a distilled water bath as outlined in paragraph 4.2.3, step 5. ➱ *The 20Ω resistor must be held at a uniform R119 Pin mV* Pin mV* Pin mV* 2 3 4 -210 -209 -204 5 6 7 -204 -199 -198 8 9 10 -195 -186 -173 *The setting of R104 and the tolerances of the resistors within the network (R119) can affect these levels by ± 5%. ➱➱ 5. Deintegrate Comparators: U103A PIN 3 to = 150 ±25mV U103B, PIN 6 to = -150 ± 25 mV 6. Cold Junction Voltage: (Ambient temperature 25º ±3ºC) -COM to = 1.0 ±0.6 mV temperature during calibration. ➱ 4.5.2 Figure 4-3. Calibration Setup for Model 872A DC Voltage Checks For Model 872A ➱➡ 1. Battery: VBAT > 7 V 2. Power Supplies: V + to (Analog Ground) = +2.8 ± 0.4 V V + to (Digital Ground) = +5 + 1 V 3. Reference Diode: CR101 to (Analog Ground)= -1.23 ±0.03 V 4. Negative Reference Divider: (Reference to Analog Ground) ➱ ➱ R119 4.3.4 Calibration Procedure It is not necessary to disassemble the case for calibration. All adjustments are accessible by removing the covers shown in Figure 4.2. 1. Remove the battery and trimmer compartment covers from the Model 872A. 2. Turn the Model 872A on and perform the calibration adjustments listed in Table 4-4. Pin mV* Pin mV* Pin mV* TABLE 4-4 2 3 4 -312 -293 -277 5 6 7 -274 -272 -271 8 9 10 -267 -254 -242 CALIBRATION ADJUSTMENTS FOR MODEL 872A *The setting of R104 and the tolerances of the resistors within the network (R119) can affect these levels by ±5%. ➱➱ 5. Deintegrate Comparators: U103, Pin 3 to =190 ±30 mV U103B, Pin 6 to = -180 ±30 mV 6. Cold Junction Voltage: (Ambient temperature 25º ±3ºC) -COM to = 1.3 mV ±0.6 12 Step 1 2 3 4 5 Adjustment Input Offset Null + Gain (X1) + Gain (X10) - Gain ºF Offset 872A Range 200ºC 760ºC 200ºC 200ºC 200ºF ➱ 9 Calibrator Setting (V) 0.0000 4.2922 1.02217 -.19604 0.000 Trimmer Adjust R109 R104 R105 R103 R102 Desired Reading 00.0ºC 760ºC 190.0ºC -40.0ºC 32.0ºF 4.4 DISASSEMBLY FOR MODEL 871A AND MODEL 872A The PC board and LCD assembly are not secured once the case retaining screws are removed. Be careful not to allow the PC board and LCD assembly to fall out or shift out of position. 1. Place the unit face down on a bench or other similar surface and remove the battery compartment cover. Remove and disconnect the battery. Remove the two #4-40 x 7/8 retaining screws. 2. Grasp the bottom cover at the input jack end and with a lifting and forward pushing motion (see Figure 4-4 and Figure 4-5), carefully remove the bottom cover. While removing the cover, feed the battery connector through the access hole in bottom of the battery compartment. 3. The component side of the PC board is now exposed and the battery can be reconnected for troubleshooting. To read the display, some light downward pressure at the top end of the circuit board may be required in order to make contact through the conductive elastomer strip, between the circuit board and the LCD. 4. To remove the PC board from the top cover, grasp the TC switch assembly and lift until the input jacks become disengaged from the cover. The PC board can now be removed using a slight clockwise motion to free the two switch knobs from their normal positions in the case. 5. The LCD assembly will remain in the top cover when the PC board is removed. Again, be careful not to allow the LCD assembly to fall out accidentally. 6. The two switch knobs can be removed from the PC board assembly by simply pulling them off the switch shafts. 7. The LCD assembly, along with the strip connector, lifts out of the case. 8. To reassemble the unit, reverse the above procedure. NOTE Proper alignment of the strip connector is necessary when reinstalling the LCD assembly. Make sure that the conductor side of the strip connector is positioned against the plastic support of the assembly. WARNING Be sure to replace the on-off switch cover. Common-mode voltage will be present on the switch, creating a possible hazard if the cover is not replaced 10 Figure 4-4. Removing the Cover Figure 4-5. Disassembled Model 871A and Model 872A 4.5 TROUBLESHOOTING GUIDE The troubleshooting information is intended to be used by qualified electronic maintenance personnel who are familiar with the proper use of standard electronic test equipment. To gain access to the PC board, refer to the first three paragraphs of the disassembly instructions. Utilize the Parts List, Schematic and Component Layout for identifying parts and checkpoint locations. The following checks should be made with the Models 871A and 872A set to the 200ºC Range. 11 4.5.1 DC Voltage Checks For Model 871A 1. Battery: VBAT > 7 V 2. Power Supplies: V + to È (Analog Ground) = +2.8 ± 0.4 V V + to È (Digital Ground) = +5 ± 1 V 3. Reference Diode: CR101 to È (Analog Ground) = -1.23 ± 0.03 V 4. Negative Reference Divider: (Reference to È Analog Ground) R119 Pin mV* Pin mV* Pin mV* 2 3 4 -210 -209 -204 5 6 7 -204 -199 -198 8 9 10 -195 -186 -173 *The setting of R104 and the tolerances of the resistors within the network (R119) can affect these levels by ± 5%. 5. Deintegrate Comparators: U103A PIN 3 to È = 150 ±25mV U103B, PIN 6 to È = -150 ± 25 mV 6. Cold Junction Voltage: (Ambient temperature 25º ±3ºC) -COM to È = 1.0 ±0.6 mV 4.5.2 DC Voltage Checks For Model 872A 1. Battery: VBAT > 7 V 2. Power Supplies: V + to È (Analog Ground) = +2.8 ± 0.4 V V + to È (Digital Ground) = +5 + 1 V 3. Reference Diode: CR101 to È (Analog Ground)= -1.23 ±0.03 V 4. Negative Reference Divider: (Reference to È Analog Ground) R119 Pin mV* Pin mV* Pin mV* 2 3 4 -312 -293 -277 5 6 7 -274 -272 -271 8 9 10 -267 -254 -242 *The setting of R104 and the tolerances of the resistors within the network (R119) can affect these levels by ±5%. 5. Deintegrate Comparators: U103, Pin 3 to È =190 ±30 mV U103B, Pin 6 to È = -180 ±30 mV 6. Cold Junction Voltage: (Ambient temperature 25º ±3ºC) -COM to È = 1.3 mV ±0.6 12 4.5.3 Waveform Checks For Model 871A Waveform Checks: Referenced To È (Digital Ground) Clock A/D Clock Ref. Clock 1 Ref. Clock 2 Backplane 4.5.3 U111, Pin 3 U112, Pin 5 U102, Pin 9 U102, Pin 14 U101, Pin 20 360 kHz, 40 kHz, 60 kHz, 6 kHz, 50 Hz, 5V pp Square Wave 5V pp Rectangular Wave 5V pp Rectangular Wave 5V pp Rectangular Wave 5V pp Rectangular Wave Waveform Checks For Model 872A Waveform Checks: Referenced To È (Digital Ground) Clock A/D Clock Ref. Clock 1 Ref. Clock 2 Backplane SECTION 5 U111, Pin 3 U112, Pin 5 U102, Pin 9 U102, Pin 14 U101, Pin 20 360 kHz, 40 kHz, 90 kHz, 9 kHz, 50 Hz, 5V pp 5V pp 5V pp 5V pp 5V pp Square Wave Rectangular Wave Rectangular Wave Rectangular Wave Rectangular Wave SPECIFICATIONS FOR MODEL 871A AND MODEL 872A GENERAL THERMOCOUPLE INPUTS: Two, switch selected ACCURACY: ±0.25% of reading +1ºC (0.25% ±1.8ºF) for one year, 64º to 82ºF (10º to 28ºC) ambient EXTENDED SPAN ACCURACY: -40º to -55ºC: +2ºC, -0ºC REPEATABILITY: ±0.2ºC Typical (one hr., constant ambient temperature) TEMPERATURE COEFFICIENT: 64º to 82ºF (18º to 28ºC); Less than ±(0.025% of reading +0.1ºC) 1ºC; for temperatures less than 64ºF (18ºC) or greater than 82ºF (28ºC) MAXIMUM ALLOWABLE TC INPUT OVERLOAD: 35Vdc (42 V peak AC) NORMAL MODE REJECTION RATIO: Greater than 45 dB at 50 and 60 Hz COMMON MODE REJECTION RATIO (1KΩ UNBALANCE): Greater than 120 dB at dc, 50 and 60 Hz DISPLAY: MAXIMUM COMMON MODE VOLTAGE: 3¹⁄₂ digit LCD, 0.6" height. Polarity and decimal point indication 500 V 13 SPECIFICATION (con’t) ENVIRONMENTAL LIMITS OPERATING: 32º to 122º F (0º to 50ºC), less than 80% relative humidity up to 95ºF (35ºC), less than 70% relative humidity from 95º to 122ºF (35º to 50ºC); linearly derate 3% R.H./ºC 35º to 60ºC. STORAGE: -30º to 140ºF (-35º TO 60ºC), less than 90% relative humidity up to 95ºF (35ºC); linearly derate 3% R.H./ºC 35º to 60ºC. COLD-JUNCTION COMPENSATION: Semiconductor temperature sensor INPUT CONNECTIONS: OMEGA subminiature thermocouple connector (2) mV OUTPUT CONNECTION: Dual banana jacks POWER: 9 V alkaline or carbon-zinc (NEDA 1604) battery BATTERY LIFE CONTINUOUS: 100 hrs. typical with alkaline battery; 50 hrs. typical with carbon-zinc battery BATTERY INDICATOR: Display indicates “BAT” when less than 10% of life remains DIMENSIONS: H: 7.0" (178 mm) x W: 3.1" (78 mm) x D: 1.6" (42 mm) WEIGHT: 10.6 oz. (300 grams) FOR MODEL 871A TEMPERATURE SENSOR: Type K (NiCr-NiAI) thermocouple RANGES: 200ºF, 2000ºF, 200ºC, 1370ºC TEMPERATURE SPAN: -40.0º to 199.9ºF, -40º to 1999ºF -40.0º to 199.9ºC, -40º to 1370ºC RESOLUTION: 0.1ºF, 1ºF, 0.1ºC, 1ºC INPUT CURRENT: 200nA maximum CONVERSION PERIOD: 400 ms (2.5 readings per sec) OVERRANGE AND OPEN THERMOCOUPLE INDICATION: Display blanked except for overrange digit 14 SPECIFICATION (con’t) mV OUTPUT: Non-linearized, cold-junction compensated, amplified thermocouple output (Not isolated from selected TC input.) On ºC Scale: 1mV/ºC on 200º range 0.1mV/ºC on 1370º range 0ºC = OmV output On º F Scale: 5/9 mV/ºF on 200º range 5/90 mV/ºF on 2000º range 0ºF = OmV output mV OUTPUT ACCURACY (18º - 28ºC) ±(3% + 1mV) on 200º ranges; ±(3% + 0.1mV) on High ranges Includes TC non-linearity, excludes TC errors. Output resistance: 10k ohms mV OUTPUT TEMPERATURE COEFFICIENT (0º - 18ºC & 28º 50ºC): mV OUTPUT PROTECTION: Less than (0.1 x accuracy specification)/ºC 35 V dc (42 V peak) max; +mV to -mV and selected TC input to +mV or -mV. THERMOCOUPLE LINEARIZATION: Multi-scope A/D with 11 piecewise linear segments between -40º and 1370ºC FOR MODEL 872A TEMPERATURE SENSOR: Type J (Fe-CuNi) thermocouple RANGES: 200ºF, 1400ºF, 200ºC, 760ºC TEMPERATURE SPAN: -40.0º TO 199.9ºF, -40º to 1400ºF -40.0º TO 199.9ºC, -40º to 760ºC RESOLUTION: 0.1ºF, 1ºF, 0.1ºC, 1ºC INPUT CURRENT: 25 nA typical; 50 nA max CONVERSION PERIOD: 400 ms (2.5 readings/sec.) OVERRANGE AND OPEN THERMOCOUPLE INDICATION: 3 least significant digits blanked 15 SPECIFICATION (con’t) mV OUTPUT: Non-linearized, cold-junction compensated, amplified thermocouple output (Not isolated from selected TC input.) On ºC Scale: 1mV/ºC on 200º range 0.1mVºC on 760º range 0ºC = OmV output On ºF Scale: 5/9 mV/ºF on 200º range 5/90 mV/ºF on 1400º range 0ºF = OmV output mV OUTPUT ACCURACY (18º - 28º C) mV OUTPUT TEMPERATURE COEFFICIENT (0º - 18ºC & 28º - 50°C) ±(5% + 1mV) on 200º ranges; ±(5% + 0.1mV) on High ranges Includes TC non-linearity, excludes TC errors. Output resistance: 10k ohms Less than (0.1 x accuracy specification)/ºC mV OUTPUT PROTECTION: 35 V dc (42 V peak) max; +mV to -mV and selected thermocouple input to +mV or -mV. THERMOCOUPLE LINEARIZATION: Multi-scope A/D with nine piecewise linear segments between -40º and 760º C 5.1 PARTS LIST Circuit Desig. Description Circuit Desig. Description BT101 C101 C102* Battery, 9V NEDA 1604 Cap, 0.22 µF, 100 V, Polyester Cap, 0.1 µF, 160 V, Polypropylene Cap, 0.1 µF, 100 V, Polypropylene Cap, 470pF, 1000 V, Ceramic Disc Cap, 220pF, 1000 V, Ceramic Disc Cap, 10 µF, 16 V, Aluminum Electrolytic Cap, 33pF, 1000 V, Ceramic Disc Cap, 47pF, 1000 V, Ceramic Disc Cap, 0.1 µF, 16 V, Ceramic Cap, 0.1 µF, 50 V, Ceramic Cap, 4.7 µF, 16 V, Aluminum Electrolytic Diode, Low Voltage Reference Liquid Crystal Display, 31⁄2 digit TC Connector, Female Jack, Female SMP Connector Jack, Female Connector, Battery Connector, Battery Transistor, NPN, Switch, 2N3904 Thick Film Resistor Network R102 R103 R104 R105 R106* Pot, 100 kΩ Pot, 2 kΩ Pot, 1 kΩ Pot, 500 Ω Resistor, 180 kΩ, 5%, 1/4W, Comp Resistor, 240 kΩ, 5%, 1/4W, Comp Resistor, 47 kΩ, 5%, 1/4W, Comp Resistor, 470 kΩ, 5%, 1/4W, Comp Pot, 2 kΩ Thick Film Resistor Network Resistor, 10 kΩ, 10%, 2W, Comp Resistor, 10 MΩ, 10%, 1/4W, Comp Resistor, 5.1 kΩ, 5%, 1/4W, Comp Resistor, 1 MΩ, 5%, 1/4W, Comp Resistor, 1 MΩ, 10%, 1/4W, Comp Resistor, Selected, 1%, 1/8W, Mtf. R115 and U110 are a selected set C102** C103 C104 C105, 106 C107 C108 C109* C109** C110** CR101 DS101 J101, 102 J103, J104** J104, 105* J105** J106* Q101, 102 R101 R106** R107 R108 R109 R110 R111 R112 R113 R114* R114** R115, 116* R115** 16 TABLE 3-1 5.1 Circuit Desig. Description Circuit Desig. CONTROLS AND INDICATORS R116** R116, R122, and U109 are a selected set Thick Film Resistor Network Resistor, 150 kΩ, 5%, 1/4W, Comp Resistor, 5.6 kΩ, 5%, 1/4W, Comp Thick Film Resistor Network Resistor, 10 kΩ, 5%, 1/4W, Comp Resistor, 10.0 kΩ, 6.1%, Metal Film Resistor , Selected, 5%, 1/4W, Comp R116, R122, and U109 are a selected set Resistor, 324 kΩ, 1%, 1/8W, Mtf. Resistor, 316 kΩ, 1%, 1/8W, Mtf. Resistor, 10.0 Ω, 0.1%, Metal film Resistor, 10 kΩ, 0.1%, MF Resistor, 9.9 kΩ, 0.1%, MF Resistor, 4.7 kΩ, 5%, 1/4 W, Comp Switch, Rotary Switch, Rotary Switch, SPDT, ON-OFF TC Cable U101 R117 R118* ITEM CONTROL/INDICATOR FUNCTION R118** 1. ON/OFF switch Turns unit on or off. R119 R120 2. Scale and range selector Allows user to select: ºF or ºC scale, any of four possible thermocouple ranges, and 1.0º or 0.1º resolution. R121** R122*† R122** 3. 4. 5. 6. 7. PARTS LIST (continued) MODEL 871A AND MODEL 872A Thermocouple selector Thermocouple input jacks Analog output jack, +mV OUT and -mV OUT Low battery indicator Overrange/open thermocouple indication Allows user to read either of two thermocouples by simply turning the dial. Allows direct connection of two thermocouples to the unit via an OMEGA miniature male connector. The analog output is a nonlinearized, cold junction compensated, amplified thermocouple output. (Not isolated from selected TC input.) Use a recorder to monitor temperature or a sensitive DMM to make higher resolution reading. Refer to mV output specifications for mV output to temperature ratios. When the battery level is low, BAT will appear in upper left corner of the display. Battery should then be replaced to avoid error erroneous readings due to battery failure. R123* R123** R124** R126* R127* R128* S101 S102 S103 TC-1, 2 U102 U103, U104* U103, U104** U105 U106 U107 U108 U109* U109** U110* U110** U111 U112 U113 U114 Y101 1 3 ⁄2 Digit Single Chip A/D Converter Dual Synchronous Up Counter Low Power JFET Input Op Amp Dual JFET Input Op Amp COS/MOS Quad Bilateral Switch CMOS Quad Exclusive OR Gate Dual “D” Type Flip-Flop 14 Stage Binary Counter Linear Op Amp R116, R222, and U109 are a selected set Current Source R115 and U110 are a selected set Quad, 2 Input NOR Gate COS/MOS Divide by “N” Counter Quad, 2 Input, AND Gate Analog Multiplexer Resonator, 360 kHz † Value selected during calibration at factory. * For Model 871A only ** For Model 872A only To order parts, specify model and circuit designation. COMPONENT LAYOUT FOR MODEL 871A R120 R127 Jumper When an overrange indication or open thermocouple condition exits, a 1 followed by blanked digits will appear in the display. COMPONENT LAYOUT FOR MODEL 872A R118A R121 Jumper R124 4 Description 17 SCHEMATIC MODEL 871A DIGITAL THERMOMETER 18 SCHEMATIC MODEL 872A DIGITAL THERMOMETER 19 MADE IN USA WARRANTY/DISCLAIMER OMEGA ENGINEERING, INC. warrants this unit to be free of defects in materials and workmanship for a period of 13 months from date of purchase. OMEGA Warranty adds an additional one (1) month grace period to the normal one (1) year product warranty to cover handling and shipping time. This ensures that OMEGA’s customers receive maximum coverage on each product. If the unit should malfunction, it must be returned to the factory for evaluation. OMEGA’s Customer Service Department will issue an Authorized Return (AR) number immediately upon phone or written request. Upon examination by OMEGA, if the unit is found to be defective it will be repaired or replaced at no charge. OMEGA’s WARRANTY does not apply to defects resulting from any action of the purchaser, including but not limited to mishandling, improper interfacing, operation outside of design limits, improper repair, or unauthorized modification. This WARRANTY is VOID if the unit shows evidence of having been tampered with or shows evidence of being damaged as a result of excessive corrosion; or current, heat, moisture or vibration; improper specification; misapplication; misuse or other operating conditions outside of OMEGA’s co n t ro l. Co mp o n e n t s w h ich wear are not warranted, including but not limited to contact points, fuses, and triacs. OMEGA is pleased to offer suggestions on the use of its various products. However, OMEGA neither assumes responsibility for any omissions or errors nor assumes liability for any damages that result from the use of its products in accordance with information provided by OMEGA, either verbal or written. OMEGA warrants only that the parts manufactured by it will be as specified and free of defects. OMEGA MAKES NO OTHER WARRANTIES OR REPRESENTATIONS OF ANY KIND WHATSOEVER, EXPRESSED OR IMPLIED, EXCEPT THAT OF TITLE, AND ALL IMPLIED WARRANTIES INCLUDING ANY WARRANTY OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE HEREBY DISCLAIMED. LIMITATION OF LIABILITY: The remedies of purchaser set forth herein are exclusive and the total liability of OMEGA with respect to this order, whether based on contract, warranty, negligence, indemnification, strict liability or otherwise, shall not exceed the purchase price of the component upon which liability is based. In no event shall OMEGA be liable for consequential, incidental or special damages. CONDITIONS: Equipment sold by OMEGA is not intended to be used, nor shall it be used: (1) as a “Basic Component” under 10 CFR 21 (NRC), used in or with any nuclear installation or activity; or (2) in medical applications or used on humans. Should any Product(s) be used in or with any nuclear installation or activity, medical application, used on humans, or misused in any way, OMEGA assumes no responsibility as set forth in our basic WARRANTY / DISCLAIMER language, and additionally, purchaser will indemnify OMEGA and hold OMEGA harmless from any liability or damage whatsoever arising out of the use of the Product(s) in such a manner. RETURN REQUESTS / INQUIRIES Direct all warranty and repair requests/inquiries to the OMEGA Customer Service Department. BEFORE RETURNING ANY PRODUCT(S) TO OMEGA, PURCHASER MUST OBTAIN AN AUTHORIZED RETURN (AR) NUMBER FROM OMEGA’S CUSTOMER SERVICE DEPARTMENT (IN ORDER TO AVOID PROCESSING DELAYS). The assigned AR number should then be marked on the outside of the return package and on any correspondence. The purchaser is responsible for shipping charges, freight, insurance and proper packaging to prevent breakage in transit. FOR WARRANTY RETURNS, please have the FOR NON-WARRANTY REPAIRS, consult following information available BEFORE OMEGA for current repair charges. Have the folcontacting OMEGA: lowing information available BEFORE contacting OMEGA: 1. P.O. number under which the product was PURCHASED, 1. P.O. number to cover the COST of the repair, 2. Model and serial number of the product under warranty, and 2. Model and serial number of product, and 3. Repair instructions and/or specific 3. Repair instructions and/or specific problems problems relative to the product. relative to the product. OMEGA’s policy is to make running changes, not model changes, whenever an improvement is possible. This affords our customers the latest in technology and engineering. OMEGA is a registered trademark of OMEGA ENGINEERING, INC. © Copyright 1996 OMEGA ENGINEERING, INC. All rights reserved. This document may not be copied, photocopied, reproduced, translated, or reduced to any electronic medium or machine-readable form, in whole or in part, without prior written consent of OMEGA ENGINEERING, INC. Where Do I Find Everything I Need for Process Measurement and Control? OMEGA…Of Course! TEMPERATURE M U M U M U M U M U Thermocouple, RTD & Thermistor Probes, Connectors, Panels & Assemblies Wire: Thermocouple, RTD & Thermistor Calibrators & Ice Point References Recorders, Controllers & Process Monitors Infrared Pyrometers PRESSURE, STRAIN AND FORCE M U M U M U M U Transducers & Strain Gauges Load Cells & Pressure Gauges Displacement Transducers Instrumentation & Accessories FLOW/LEVEL M U M U M U M U Rotameters, Gas Mass Flowmeters & Flow Computers Air Velocity Indicators Turbine/Paddlewheel Systems Totalizers & Batch Controllers pH/CONDUCTIVITY M U pH Electrodes, Testers & Accessories M U Benchtop/Laboratory Meters M U Controllers, Calibrators, Simulators & Pumps M U Industrial pH & Conductivity Equipment DATA ACQUISITION M U M U M U M U M U Data Acquisition & Engineering Software Communications-Based Acquisition Systems Plug-in Cards for Apple, IBM & Compatibles Datalogging Systems Recorders, Printers & Plotters HEATERS M U M U M U M U M U Heating Cable Cartridge & Strip Heaters Immersion & Band Heaters Flexible Heaters Laboratory Heaters ENVIRONMENTAL MONITORING AND CONTROL M U M U M U M U M U M U Metering & Control Instrumentation Refractometers Pumps & Tubing Air, Soil & Water Monitors Industrial Water & Wastewater Treatment pH, Conductivity & Dissolved Oxygen Instruments M618/0896
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File Type : PDF File Type Extension : pdf MIME Type : application/pdf PDF Version : 1.4 Linearized : No Create Date : 1999:07:30 06:09:13Z Modify Date : 2005:03:10 13:30:35-06:00 Keywords : thermocouple, thermocouples, rtd, temperature control, temperature measurement, resistance temperature device, resistance temperature, temperature sensor, thermocouple probe, thermacouple, thermocuple, thermalcouple, infrared temperature, ir, infrared, meter, panel meter, multimeter, multimeters, multi meter, meter, meters, temperature controller, process control, temperature transmitter, thermowell, thermistor, thermistors, thermocouple wire, electric heater Page Count : 24 Creation Date : 1999:07:30 06:09:13Z Producer : Acrobat Distiller 3.01 for Power Macintosh Author : Omega Engineering Mod Date : 2005:03:10 13:30:35-06:00 Metadata Date : 2005:03:10 13:30:35-06:00 Creator : Omega Engineering Title : Handheld Temperature MetersEXIF Metadata provided by EXIF.tools