Extech Instruments 42311, 42312 User Manual

User’s Guide

Digital Thermocouple
Calibrator & Thermometer

Models:
42311 Type J
42312 Type K

Introduction

Congratulations on your purchase of Extech model 42311 or 42312 Digital Thermometer and
Calibrator. Properly used, this meter will provide many years of reliable service.

V1.5 1/03

2

WARRANTY

EXTECH INSTRUMENTS CORPORATION warrants this instrument to be free of defects in
parts and workmanship for one year from date of shipment (a six month limited warranty
applies on sensors and cables). If it should become necessary to return the instrument for
service during or beyond the warranty period, contact the Customer Service Department at
[phone] ext. 210 for authorization. A Return Authorization (RA) number must be
issued before any product is returned to Extech. The sender is responsible for shipping
charges, freight, insurance and proper packaging to prevent damage in transit. This warranty
does not apply to defects resulting from action of the user such as misuse, improper wiring,
operation outside of specification, improper maintenance or repair, or unauthorized
modification. Extech specifically disclaims any implied warranties or merchantability or fitness
for a specific purpose and will not be liable for any direct, indirect, incidental or consequential
damages. Extech's total liability is limited to repair or replacement of the product. The
warranty set forth above is inclusive and no other warranty, whether written or oral, is
expressed or implied.

Safety Precautions

1. Make sure any covers or battery doors are properly closed and secured.

2. Remove the battery from the meter if the meter is to be stored for long periods.

3. Touching the thermocouple to a device which is powered electrically can cause
damage to the meter and may pose a shock hazard.

4. To avoid damage do not make temperature measurements in microwave ovens.

Specifications

Display 3 ½ digit (1999 Count) LCD (Liquid Crystal Display)

Temperature Scale ºC or ºF (user-selectable)

Thermocouple type Model 42311: type J; Model 42312: type K

Measurement and Model 42312: -40º to 2000ºF (-40º to 1350ºC)
Source Ranges Model 42311: -40º to 1400ºF (-40º to 760ºC)

Resolution 1ºC/F or 0.1ºC/F (< 200ºF/C)

Accuracy ±(0.1% rdg + 2ºF) or ±(0.1% rdg + 1ºC)

Temp. Coefficient 0.1 times the applicable accuracy spec per ºC or ºF from

32º to 64ºF and 82º to 122ºF (0º to 18ºC and 28º to 50ºC)

Input Protection 24VDC or 24VAC RMS maximum input voltage

Display Update 2.5 times per second

Input Connector Accepts standard subminiature thermocouple connectors

Battery 9V battery (200 hour typical battery life)

Dimensions/Weight 7.5x3.54x2.1 inches (190x90x53 mm) / 1 lb (440g)