Fluke RUSKA 7252, Руководство пользователя, Страница: 109 / 128

Maintenance
Optimizing Control
6
6-17
There are three options available to the operator.
Full This fully characterizes the control function of the RUSKA 7252. It
automatically adjust the control valve biases and aligns the inner loop high
control pressure sensor to the high accuracy quartz sensor. This should be
performed any time major components are replaced in the controller such
as the control valves or the high-speed inner loop control sensor.
Additionally, if the controller is not functioning properly, a full Auto-tune
can be performed to optimize the control.
Calibrate This automatically aligns the inner loop high control pressure sensor to the
high accuracy quartz sensor. If in the Normal control mode (as opposed to
the fast control mode), the controller overshoots the commanded pressure
valve, this could be an indication that the inner loop control sensor needs to
be realigned with the high accuracy quarts sensor. This is achieved by
running the Calibrate Auto-Tune function.
Valves This automatically adjusts the control valve biases. This adjustment can
compensate for long-term valve changes and adjust for changes to supply
pressures beyond the recommended settings.
Note
Prior to performing any Auto-Tune functions in an effort to improve the
controller performance, confirm that the system is a leak free system and
the volume attached to the test port is within the recommended range
(see Appendix A). Additionally, assure that the system has adequate
pressure and vacuum supply (when required).
To perform these Auto-Tune functions, the instrument must be connected to a pressure
supply with the pressure supply set to the proper supply pressure (Refer to the
specifications in Appendix A). On absolute instruments, a vacuum pump must be
connected to the exhaust port.
Disconnect any device under test from the test port. The test port must be connected to a
sealed volume of 5 to 15 cubic inches (80 to 240 cc’s).
Use the Rotary knob to select which Auto-Tune procedure is to be performed and then
press the enter key. Select Full to perform the complete Auto-Tune sequence. If selected,
you are not required to run any of the other Auto-Tune functions. Press the enter key.
The Calibrator with go through a sequence of controlling to various pressures and
automatically adjusting the control parameters of the valves. The Calibrator will display a
message indicating when it has completed the Auto-Tune procedure. The time required to
complete the Auto-tune procedure can range anywhere from 15 to 45 minutes.