B - calculate absolute accuracy and accuracy drift, Overview, Calculate with formulas – Rockwell Automation 1734-IT2I Thermocouple and RTD Input Module User Manual User Manual

Page 79: Absolute accuracy formula, Accuracy drift formula, Appendix b, Calculate absolute accuracy and accuracy drift, Overview calculate with formulas, Absolute accuracy formula accuracy drift formula, Appendix

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Publication 1734-UM004F-EN-E - December 2012

Appendix

B

Calculate Absolute Accuracy and
Accuracy Drift

Overview

The Absolute Accuracy and Accuracy Drift with temperature specification
applies only to mV input for 1734-IT2I, and to ohms input for 1734-IR2 and
1734-IR2E modules. These specifications are listed in the POINT I/O RTD
and Isolated Thermocouple Input Module Installation Instructions,
publication

1734-IN011

.

Use mV input (1734-IT2I) or ohms input (1734-IR2 and 1734-IR2E) to verify
the Absolute Accuracy or Accuracy Drift of the POINT I/O modules.

Calculate with Formulas

Here are the formulas for calculating Absolute Accuracy and Accuracy Drift in
mV or ohms.

Absolute Accuracy Formula

Absolute Accuracy measurement is to be done at 25

C. The formula to

calculate Absolute Accuracy is as follows:

[(measured value - expected value)/ full scale] x 100 %

Accuracy Drift Formula

Accuracy Drift measurement is to be done at 2 ambient Temperature points:
T1 and T2. The formula to calculate Accuracy Drift is as follows:

[(measured value (T2) - (measured value (T1)]/ [(T2 - T1) x full scale] x
1000 000

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