R
What I am looking for is an answer or direction here. The situation is this:
1. We have installed in the field several Pressure Transducers that have a 4-20 ma output.
2. The sensors are sealed and cannot be adjusted internally
3. When the calibration team does their periodic 3 yr calibration they check the system output at the display, if it is outside 1% tolerance they test the individual components.
4. The transducers must stay within 1% or they are failed and must be replaced.
The system has the ability to calibrate the output on the display using software that adjusts the span and offset equation (Mx + B). The calibration policy does not allow this to be done. I understand in certain instances using the software to make adjustments may not be acceptable (in safety or control situations) but I cannot find any real documentation on using software to calibrate a system.
I have to ask, if you treat the system as a whole from the sensor to the display and you inject a calibrated source into the transducers, use the software to calibrate and the output is a calibrated, repeatable value then why would this not be acceptable?
1. We have installed in the field several Pressure Transducers that have a 4-20 ma output.
2. The sensors are sealed and cannot be adjusted internally
3. When the calibration team does their periodic 3 yr calibration they check the system output at the display, if it is outside 1% tolerance they test the individual components.
4. The transducers must stay within 1% or they are failed and must be replaced.
The system has the ability to calibrate the output on the display using software that adjusts the span and offset equation (Mx + B). The calibration policy does not allow this to be done. I understand in certain instances using the software to make adjustments may not be acceptable (in safety or control situations) but I cannot find any real documentation on using software to calibrate a system.
I have to ask, if you treat the system as a whole from the sensor to the display and you inject a calibrated source into the transducers, use the software to calibrate and the output is a calibrated, repeatable value then why would this not be acceptable?