Endress+Hauser iTHERM TrustSens TM371, Operating Instructions Manual

Page: 96 / 106

Operating menu and parameter description iTHERM TrustSens TM371, TM372
96 Hauser
Failure current
Navigation Expert → Output → Failure current
Prerequisite The option High alarm is enabled in the failure mode.
Description Use this function to set the value the current output adopts in an alarm condition.
User entry 21.5 to 23 mA
Factory setting 22.5
Adjustment of the analog output (4 and 20 mA current trimming)
Current trimming is used to compensate the analog output (D/A conversion). Here, the
output current of the transmitter must be adapted so that it suits the value expected at the
higher-order system.
Current trimming does not affect the digital HART ® value. This can cause the
measured value shown on a locally installed display to differ from the value displayed
in the higher-order system.
Procedure
1. Start
ß
2. Install an accurate amperemeter (more accurate then the transmitter) in the current loop.
ß
3. Switch on current output simulation and set the simulation value to 4 mA.
ß
4. Measure the loop current with the amperemeter and make a note of the value.
ß
5. Set the simulation value to 20 mA.
ß
6. Measure the loop current with the amperemeter and make a note of the value.
ß
7. Enter the current values determined as adjustment values in the Current trimming 4 mA / 20 mA
parameters
ß
8. End
Current trimming 4 mA
Navigation Expert → Output → Current trimming 4 mA
Description Use this function to set the correction value for the current output at the start of the
measuring range at 4 mA.