Omega Engineering 873C, 873F Owner's Manual

r\: OMEGA

^^ ^^H FiyniiyFFDii\iG iiur

EIMGIIMEERIIMCIIMC.

In 0>lf."f» t lirwup Company

MODEL 873
Hand Held Digital

Thermometer

Operator's Manual

WARRANTY

OI\^EGA warrants this unit to be free of defects in materials and workmanship
and

to

give satisfactory service for a period of

one (1)

year

from

date of purchase.
If the unit sfiould malfunction, it must be returned to ttie factory for evaluation.
Our Customer Service Department will issue

an

Authorized Return (AR) number
immediately upon phone or written request. Upon examination by OMEGA, it
the unit is found to be defective it will be repaired or replaced at no charge.
However, 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
current, heat, moisture, vibration, or misuse, (Components which wear or which
are damaged by misuse are not

warranted.

These include contact

points,

fuses,

and triacs.
THERE ARE

NO

WARRANTIES EXCEPT AS STATED

HEREIN.

THERE ARE NO
OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING BUT NOT
LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND OF
FITNESS FOR A PARTICUUR PURPOSE. IN NO EVENT SHALL OMEGA
ENGINEERING, INC. BE LIABLE FOR CONSEQUENTIAL, INCIDENTAL OR
SPECIAL

DAMAGES.

THE BUYER'S

SOLE

REMEDY

FOR

ANY

BREACH OF THIS
AGREEMENT BY OMEGA ENGINEERING, INC. OR ANY BREACH OF ANY
WARRANTY BY OMEGA ENGINEERING, INC. SHALL NOT EXCEED THE
PURCHASE

PRICE PAID BY THE

PURCHASER

TO OMEGA

ENGINEERING,

INC.
FOR THE UNIT OR UNITS OR EOUIPMENT DIRECTLY AFFECTED BY SUCH
BREACH.

Return Requests/Inquiries

Direct all warranty and repair requests/inquiries to OMEGA Customer Service
Department, telephone number

(203)

359-1660.

Before returning any instrument, please
contact the OMEGA Customer Service Department to obtain an authorized return (AR)
numtier. The designated AR number

should

then be marked

on

the outside of

the

return

package.

To avoid processing delays, also please be sure to Include:

1.

Returnee's name, address, and phone number.

2.

Model and Serial numbers.

3. Repair instructions.

i^OMEGA

A. .^H

ENGiniEERING,

IIMC

One Omega Drive, Box 4047

Stamford,

Connecticut 06907-(X)47

[phone] Telex: 996404 Cable: OMEGA

FAX: [phone]

OMEGA'-' is a registered trademark of OMEGA ENGINEERING, INC.

-, Copyright 1984 OMEGA ENGINEERING, INC. Alt rights reserved including

illustrations. Nothing in this manual may be reproduced in any manner, either wholly

or in part for any purpose whatsoever without written permission from
OMEGA ENGINEERING, INC.

Printed in

U.S.A.

M230/025

TABLE OF CONTENTS

GENERAL INFORMATION 1

Unpacking and Inspection 1
Optional Accessories 2
Preparation for Use 3
Safety Symbols

and

Terms 4

Environmental Conditions 4

OPERATION 5

Safety Precautions 6

SERVICING INFORMATION 9

Functionality Check 9
Performance Verification 9
Environmental Conditions 10
Disassembly Instructions 10
Battery Installation/Replacement 12
Calibration 13

Probe Matching 15
Troubleshooting ...: 15
Special Handling of Static Sensitive Devices 18
Component Layout 21
Schematic Diagram 23

GENERAL INFORMATION

The OI^EGA® IVIodels 873C and 873F are Hand Held Digital Thermo­meters. Both instruments have large easy to read liquid crystal displays
(LCD).

The input connection consists of a subminiature, type K thermo­couple, female connector (SMP-K-F). This input accommodates any
OMEGA type K thermocouple probe fitted with an SMP-K-M connec­tor. Cold junction electronic circuitry

in

the 873F/873C automatically
compensates for ambient temperature changes. These instruments
also provide piece-wise linearization conformity for thermocouple non­linearity. The instruments are powered by a 9V battery. Continuous
operation of 350 hours is typical with an alkaline battery or 200 hours
typical with a carbon-zinc battery.

The Model 873C measures temperature from - 55°C to 1000°C on

two ranges. The 200°C range measures temperature from -55.0°C to

199.9°C with a resolution of 0.1°C. The 1000°C range measures
temperature from -55°C to 1000°C with a resolution of 1°C. The ac­curacy is ± (0.25% rdg

-i-

1.0°C)

from -40°C to 1000°C and ± (0.25%

of rdg -l-2°C) for -40°C to -55°C.

The Model 873F measures temperature from - 60°F to 200°F

on

two

ranges. The 200°F range measures temperature from -60.0°F to

199.9°F with a resolution of 0.1°F. The 2000°F range measures
temperature from -60°F to 1999°F with a resolution of 1°F. The ac­curacy of the Model 873°F is ±(0.25% of rdg -i-2.0°F).

UNPACKING AND INSPECTION

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 [phone].
Upon receipt of shipment, inspect the container and equipment for

any signs 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.

OPTIONAL ACCESSORIES

The following optional accessories can

be

used with the Models 873C
and 873F to enhance the performance of the instrument. These
accessories are available:

Part Number
KS871

SC800
880A2
MN1604
SMP-K-M

SMP-K-F

OT-201-1

Description
Tilt Stand/Belt Clip/Probe Holder; can

be used as a tilt stand or clipped to
your belt. It will hold one compact
probe.

Soft Carrying Case
Deluxe Carrying Case

9V Replacement Battery
Subminiature Thermocouple Connec-

tor, Male
Subminiature Thermocouple Connec-

tor, Female

1 oz jar of High Thermal Conductivity

Paste for fast surface measurements.

PREPARATION FOR USE

The Models 873F and 873C are supplied ready for use with battery
installed.

Connect the appropriate probe to the miniature TC connec-

tor located on the top of the instrument (just above the display).

SAFETY SYMBOLS AND TERMS

The symbol /!\ on the instrument denotes that the user should refer

to the opjerating instructions.
The WARNING used in this manual explains dangers that could result

in personal injury or death.
The CAUTION used in this manual explains hazards that could

damage the instrument.

ENVIRONMENTAL CONDITIONS

Operation of the Models 873C and 873F should take place at

an

am­bient temperature of -10°C to 50°C (14°F to 122°F), less than 80%
relative humidity up to 35°C, lineariy derate 3%

R.H./C

from 35°C to

60°C.

OPERATION

The 873C and 873F Hand Held Digital Thermometers are easy to use
There is only one control (located on the side of the instrument) that
turns the instrument on/off and selects the range. (See Figures 1 and

2).

Use the following procedure to operate the instrument:

1.

Turn on the power to the instrument by selecting the desired range.

Model 873C:
A. 200°C range is the center position of the ON/OFF range switch.
B. 1000°C range is the upper position of the ON/OFF range switch.

Model 873F:

A. 200°F range is the center position of the ON/OFF range switch.

B. 2000°F range is the upper position of the ON/OFF range switch.

2.

Select the appropriate temperature probe and insert it into the input

jack.

3. Make the measurement:
A. Touch the probe tip to the material to be measured.

B. Read the display. The reading is in Celsius for the Model 873C.

The reading is in Fahrenheit for the Model 873F.

NOTE

An open sensor or overrange condition is indicated by:

CAUTION
Do not attempt to measure temperatures beyond
the range of the probe being used. Probe damage
may occur.

WARNING

A shock hazard exists on the Models 8730 and 873F
Input jacks when probes

or

sensors are exposed

to

voltage levels greater than 42V peak to earth ground.

SAFETY PRECAUTIONS

1.

Do not touch the probe tip when measuring excessively high or low

temperature.

2.

Do not exceed 42V peak from the probe tip or input jack to earth

ground.

Miniature TC Connector

Low Battery Indicator

Minus Sign Displayed

•

Plus Sign Implied

3V4 Digit Display—

On/Off Range Switch

OMEGA 873C THERMOMETER

LO

BAT

-loao

200

TYPE K THEHMOCOUPLE

NiCr-N<AI

RANOE:

-IB'C

to

lOOO'C

^ 42V MAX

-^

Figure 1. Model 873C Control Layout

4

Miniature TC Connector

Low Battery Indicator^

Minus Sign Displayed-

Plus Sign Implied

VA Digit Display-

On/Off Range Switch

OMEGA 873F THEHMOMETER

^

r DM I

-\QO.U

^=

TYPE K THEIIMOCOUPI.E

NiCr-NiAl

RANOE.

-tO'E

to

2000*F

A 42V MAX

+

Figure 2. Model 873F Control Layout

SERVICING INFORMATION

This section contains information needed to maintain the Models

873C and 873R The following information is included: functional

check, performance verification, disassembly instructions, battery in-

stallation/replacement, calibration, probe matching, troubleshooting,
parts list, schematic diagram and component layout.

WARNING
The information presented in this section is in­tended for use by qualified personnel only. Turn off
the power and remove all probes from the instru­ment before replacing the battery.

FUNCTIONALITY CHECK

At room temperature hold the tip of a probe sensor between your

thumb and index finger. A reading between 25°C and 40°C (77°F and

104°F) should be observed to confirm functionality of the instrument.

PERFORMANCE VERIFICATION

Accuracy Check

1.

Prepare a distilled water ice bath or use an OMEGA* TRC III Ice

Point Reference Chamber.

2.

Connect a TC probe to the input jack of the instrument.

3. Immerse the TC probe into the TRC III or distilled water ice bath
and allow 10 minutes for thermal stabilization,

4.

Turn on the instrument and use Table 1 to verify that the readings

on each range are within specifications.

Table 1. Performance Verification

Range

200

1000

2000

873°C

0.0 ± 1°C

0 ± 1°C

873°F

32,0 ± 2°F

32 ± 2°F