Rockwell Automation 1762-IT4 Thermocouple/mV Input Module - Manual (Page 16)

Publication 1762-UM002A-EN-P - July 2002
1-6 Overview
Module Field Calibration
The module provides autocalibration, which compensates for offset
and gain drift of the A/D converter caused by a temperature change
within the module. An internal, high-precision, low drift voltage and
system ground reference is used for this purpose. The input module
performs autocalibration when a channel is initially enabled. In
addition, you can program the module to perform a calibration cycle
once every 5 minutes. See Selecting Enable/Disable Cyclic Calibration
(Word 4, Bit 0) on page 3-14 for information on configuring the
module to perform periodic autocalibration.