Zero Trim and Calibration of X'mtr

If you bench calibrate each instrument before installation, there will be fewer surprises when it comes to loop checks and start up. On the bench, there is time to fuss with it and figure out settings, while you don't have the whole crew waiting on you.

GA. Further, it means that a previously-set-up instrument can be swapped for the one in the line and the process kept going. Instrument calibration can then take place as a normal routine and not as a panic in the middle of the night while all hell is breaking loose around the poor sod who is trying to do the task!