Extech 421501 Operating Manual

User's Guide

Type K Digital Thermometer

Model 421501

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Introduction

Congratulations on your purchase of the Extech 421501 Type K Digital Thermometer.
This water resistant meter measures temperature with a Type K thermocouple. The
thermocouple attaches to the meter with a sub-miniature plug. The meter’s display is
backlit and includes a Data Hold feature. Other features include Max Temperature and
selectable units/resolution. This meter is shipped fully tested and calibrated and, with
proper use, will provide years of reliable service.

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 to 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 or visit our website
www.extech.com for contact information. 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.

Specifications

Display 3-1/2 digit LCD (2000 counts)
Battery Power Supply 9V DC battery.
Battery life 200 hours typical
Dimensions / Weight 7.5 x 3.6 x 2.1” (192 x 91 x 52.5mm); 11.7oz. (365g)
Range / Resolution -58 to 2000oF (-50 to 1300oC); 1o or 0.1oF/oC

Important Note: The supplied thermocouple can only
be used to measure temperature up to 500
To measure higher temperatures, a high temperature
Type K thermocouple must be used.

Temperature units Selectable oC or oF temperature units
Accuracy of meter

±(0.3% of reading + 1oC) from -50oC to 1000oC
±(0.5% of reading + 1oC) from 1000oC to 1300oC
±(0.3% of reading + 2oF) from -58oF to 2000oF

Temperature Coefficient 0.1 times the applicable accuracy specifications per oC

o

C to 18oC and 28oC to 50oC (32oF to 64oF and

from 0

o

F to 122oF)

82

Water resistant housing Gasket protected front panel
Input Protection 24VAC/DC max. input on any combination of inputs
Reading rate 2.5 times per second
Thermocouple connection Meter accepts standard subminiature connector
Supplied thermocouple Teflon insulated Type K thermocouple (4’ length)

Max temperature: 500

o

F (260oC); For higher

temperatures, a high temp thermocouple must be used.

o

Accuracy: ±4

F (±2.2oC) or +0.75% of rdg

(whichever is greater) from 32 to 1472

Operating conditions 32 to 122oF (0 to 50oC); less than 80% RH
Storage conditions -4 to 140oF (-20 to 60oC); less than 70% RH

o

F (260 oC).

o

F (0 to 800oC)

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Model 421501 Version 1.3 February 2006