Instrumentation & Calibration
Control Valve Stroke Calibration
Record a full five-point upscale and downscale stroke cycle, compare actual travel with expected position, and screen the direction-dependent travel difference at each command.
What this tells you
The point error is a direct command-versus-travel check of the valve/positioner assembly. The paired upscale/downscale difference is useful for screening direction-dependent behavior associated with friction, backlash, hysteresis or deadband.
It does not isolate formal hysteresis from deadband. A dedicated reversal test or diagnostic valve signature is required when that distinction matters.
Field discipline
Stroke the valve only where the process, bypass arrangement, actuator energy and permit conditions make it safe. Record whether the test is on the bench, in place, online, or isolated. Do not infer fail-open/fail-closed action from the command direction used here.