Search the Community
Showing results for tags 'ai8 non-linear'.
Found 1 result
-
During calibration of a pressure sensor (4-20ma) I was unable to achieve an precise calibration 0 to 30.00 PSIA within 0.7 PSIA at the lower or upper range when using the scaling functions. The sensor was calibrated from the manufacture within 0.1% accuracy. I decided to check the Analog Input with a calibrated Fluke Processmeter from: 4.000 ma to 20.000ma. The Hardware was configured for 4-20ma input and default scaling 0 to 8191 inputs with strong filtering enabled. Unilogic version 1.22.13 Here are the results: Fluke(ma) Actual Count Expected Count Count Diff. 4.0000 -45 0 -45 6.0000 954 1024 -70 8.0000 1954 2048 -94 12.0000 3953 4096 -143 14.0000 4957 5119 -162 16.0000 5951 6143 -192 18.0000 6951 7167 -216 20.0000 7949 8191 -242 The counts are non-linear corresponding to the 4-20ma inputs, i would expect the counts difference to be constant. I was not able to check all the channels, but could this be just a bad channel or are the values within the specification of the AI card?
