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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
c o n t r o l .   C o m p o n e n t s   w h i c h   w e a r   a r e   n o t   w a r r a n t e d ,   i n c l u d i n g   b u t   n o t   l i m i t e d   t o
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 compo-
nent upon which liability is based. In no event shall OMEGA be liable for consequential, inciden-
tal 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

following information available BEFORE 
contacting OMEGA:
1. P.O. number under which the product was 

PURCHASED,

2. Model and serial number of the product under

warranty, and

3. Repair instructions and/or specific 

problems relative to the product.

FOR 

NON-WARRANTY

REPAIRS, consult

OMEGA for current repair charges. Have the fol-
lowing information available BEFORE 
contacting OMEGA:
1.  P.O. number to cover the COST 

of the repair,

2. Model and serial number of product, and
3. Repair instructions and/or specific problems 

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.

USA   

  

MADE

IN

Содержание 871A

Страница 1: ...http www omega com e mail info omega com User sGuide 871A and 872A Digital Thermometers Only model 871A has CE certification ...

Страница 2: ...ree 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 ISO 9002 Certified Broughton Astley Leicestershire Irlam Manchester LE9 6TU England M44 5EX England Tel 44 1455 285520 Tel 44 161 777...

Страница 3: ... 4 1 2 Accuracy Check 6 4 2 Calibration for Model 871A 6 4 2 1 Equipment Needed 6 4 2 2 Environmental Conditions 6 4 2 3 Setup 7 4 2 4 Calibration Procedure 7 4 3 Calibration for Model 872A 8 4 3 1 Equipment Needed 8 4 3 2 Environmental Conditions 8 4 3 3 Setup 8 4 3 4 Calibration Procedure 9 4 4 Disassembly for Model 871A and Model 872A 10 4 5 Troubleshooting Guide 11 4 5 1 DC Voltage checks Mode...

Страница 4: ... 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 req...

Страница 5: ...in the event reshipment is necessary 2 2 BATTERY INSTALLATION 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 connecti...

Страница 6: ...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 ...

Страница 7: ...Analog output jack The analog output is a nonlinearized mV OUT and mV OUT 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 ...

Страница 8: ...NFORMATION 4 1 VERIFICATION CHECK 4 1 1 Functionality Check 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 Range Span Resolution 200 F 40 0 to 199 9 F 0 1 F 200...

Страница 9: ...quipment Needed 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 transi tion junction see paragraph 4 2 3 4 2 2 Environmental Conditions To meet all specifications...

Страница 10: ...k 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...

Страница 11: ... 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 OM...

Страница 12: ...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 TABLE 4 4 CALIBRATION ADJUSTMENTS FOR MODEL 872A 9 872A Calibrator Trimmer Desired Step...

Страница 13: ...ontact 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 cove...

Страница 14: ...aintenance personnel who are familiar with the proper use of stan dard 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 ...

Страница 15: ...5mV 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 2 312 5 274 8 267 3 293 ...

Страница 16: ...tangular Wave Backplane U101 Pin 20 50 Hz 5V pp Rectangular Wave SECTION 5 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 ...

Страница 17: ...al 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 20...

Страница 18: ... OUTPUT TEMPERATURE COEFFICIENT 0º 18ºC 28º 50ºC Less than 0 1 x accuracy specification ºC mV OUTPUT PROTECTION 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...

Страница 19: ...4W Comp R107 Resistor 47 kΩ 5 1 4W Comp R108 Resistor 470 kΩ 5 1 4W Comp R109 Pot 2 kΩ R110 Thick Film Resistor Network R111 Resistor 10 kΩ 10 2W Comp R112 Resistor 10 MΩ 10 1 4W Comp R113 Resistor 5 1 kΩ 5 1 4W Comp R114 Resistor 1 MΩ 5 1 4W Comp R114 Resistor 1 MΩ 10 1 4W Comp R115 116 Resistor Selected 1 1 8W Mtf R115 R115 and U110 are a selected set SPECIFICATION con t mV OUTPUT Non linearized...

Страница 20: ...rcuit Description Desig U101 3 1 2 Digit Single Chip A D Converter U102 Dual Synchronous Up Counter U103 U104 Low Power JFET Input Op Amp U103 U104 Dual JFET Input Op Amp U105 COS MOS Quad Bilateral Switch U106 CMOS Quad Exclusive OR Gate U107 Dual D Type Flip Flop U108 14 Stage Binary Counter U109 Linear Op Amp U109 R116 R222 and U109 are a selected set U110 Current Source U110 R115 and U110 are ...

Страница 21: ...SCHEMATIC MODEL 871A DIGITAL THERMOMETER 18 ...

Страница 22: ...SCHEMATIC MODEL 872A DIGITAL THERMOMETER 19 ...

Страница 23: ...otherwise shall not exceed the purchase price of the compo nent upon which liability is based In no event shall OMEGA be liable for consequential inciden tal 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 huma...

Страница 24: ...heel Systems M U 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 Data Acquisition Engineering Software M U Communications Based Acquisition Systems M U Plug in Cards for Apple IBM Compatibles M U Datalogging Systems M U Recorde...

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