Rockwell Automation 1756-CFM ControlLogix Configurable Flowmeter Module - Manual (Page 141)

141 Rockwell Automation Publication 1756-UM010B-EN-P - December 2011
Appendix
D
Frequency Accuracy
Use this appendix to calculate the frequency accuracy for high resolution
frequency mode and totalizer mode.
Frequency Accuracy in
High Resolution
Frequency Mode
There are two steps to calculating frequency accuracy in high resolution
frequency mode.
1. Calculate frequency accuracy.
2. Determine the application’s operating conditions and add the error for
those conditions to the value obtained in step 1.
The following values must be added to your frequency accuracy results
in totalizer mode:
 Crystal error - 0.005% @ 25°C
 Drift and crystal error - 0.01% from 0° to 60°C
Calculate Frequency Accuracy
When calculating frequency accuracy in high resolution frequency mode, you
must know:
 sample time period
 input frequency