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Page 1                                                                                                                 Model 421508   Version 1.0   October 2002 

 

INSTRUCTION MANUAL 

 

Model 421508

 

 
Dual Input, 3-Display Handheld Thermometer 

 
 
 
 
 

  Accepts J, K, T, E, R, S, & N thermocouples 

 
 

  Backlit Electro-luminescent LCD Display 

 
 

  T1 / T2 / T1 – T2 displays 

 
 

  MIN / MAX / AVG Record/Recall 

 
 

  Selectable temperature units (C/F) 

 
 

  Data Hold, Relative Mode, Elapsed Timer 

 
 

  Bi-directional RS-232 PC Interface 

 
 
 
 
 
 
 
 
 
 
 
 
 

Introduction 

Congratulations on your purchase of Extech’s Dual Input, 3-Display, Hand-Held Digital 
Thermometer. This portable digital thermometer is designed to use external K / J / T / E / R 
/ S / N type thermocouples (K-type supplied). Temperature indication follows Reference 
Temperature/Voltage Tables (N.I.S.T. Monograph 175 Revised to ITS-90). This 
professional meter, with proper care, will provide years of safe reliable service. 

 

Summary of Contents for 421508

Page 1: ... Hold Relative Mode Elapsed Timer Bi directional RS 232 PC Interface Introduction Congratulations on your purchase of Extech s Dual Input 3 Display Hand Held Digital Thermometer This portable digital thermometer is designed to use external K J T E R S N type thermocouples K type supplied Temperature indication follows Reference Temperature Voltage Tables N I S T Monograph 175 Revised to ITS 90 Thi...

Page 2: ...ther ranges T type 328 to 752 o F 200 to 400 o C 0 1 o F 0 1 o C from 0 to 600 o F 0 2 o F all other ranges E type 346 to 1454 o F 210 to 790 o C 0 1 o F 0 1 o C from 0 to 450 o F 0 2 o F all other ranges R type 32 to 3212 o F 0 to 1767 o C 1 o F 1 o C S type 32 to 3212 o F 0 to 1767 o C 1 o F 1 o C N type 58 to 2372 o F 50 to 1300 o C 0 2 o F 0 1 o C Accuracy Specifications Thermocouple Accuracy ...

Page 3: ...r burns do not make temperature measurement in microwave ovens CAUTION Repeated flexing can break the thermocouple leads To prolong lead life avoid sharp bends in the leads especially near the connector This symbol on the instrument indicates that the operator must refer to an explanation in this manual Meter Description 1 Thermocouple inputs 2 Optical PC Interface 3 LCD Display 4 Keypad 5 Rubber ...

Page 4: ...se the TYPE key to select the thermocouple type K J T E R S or N that is connected to the T1 input The thermocouple type is indicated on the left side of the LCD When the thermometer is turned on it remembers the type used when the thermometer was last turned off MIN MAX Key Note Auto Power OFF and several keys C F REL SET HI LO TYPE and T1 T2 T1 T2 are defeated in this mode Press MIN MAX to enter...

Page 5: ...r the programmed data and queue the next SET parameter a Setting the Relative Mode reference value Press the SET key to enter the Relative value setting mode When in this mode dashes are displayed on the main display Manually program the desired value via the numeric keys Press the ENTER key to store the relative value and move to the High Low Limit setting mode b Setting the High and Low Alarm Li...

Page 6: ...e Extech recommends that calibration be performed on an annual basis to ensure calibration integrity 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 warra...

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