Questions Regarding Testing of Process Controls

[jmltinc]

Hello Folks,

I am working on a paper regarding the in situ testing of the response time of process controls. These methods are not passive but require small, but regular deviation from normality during testing. Described in this paper are two methods of testing - one which is particularly useful for pressure sensors, but requires superficial modifications to the sensor (the vent) and slightly changes its characteristic while testing. The other varies a process itself within its set points (in particular the RCS), but allows testing of all process controls.

Can anyone point me to a specific regulation regarding variation of procedure and modification of equipment?

Thank you,
-John