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PPC4 - Calibrate a PPC4 that's used to Autofloat a PG7000 Piston Gauge

The PPCx (PPC4, or PPC2+, or PPC3, or PPCH or PPCH-G) that's used to Autofloat the piston of a PG7000 Piston Gauge can be calibrated in-situ like any other instrument.  This means that the PPCx would be serving dual roles of AutoFloat controller and as a DUT.  However because the PPC is electrically connected to the PG7000 by a RS232 cable, and because the PPC is controlled by the PG7000 there is a unique scheme and a special command ("PPCPR") is required to interface the PPC through the PG7000.

A typical setup for a PPCx with a PG7000:

The first step is to setup the PPC in COMPASS for Pressure as a DUT. This example is for a PPC4.



Press the [Edit Commands] button to add a read command. Enter the info like below and save the command by pressing the black/white disk icon.


Press the black/white disk icon to save the record.

Run a normal test in COMPASS for Pressure using the "Run Test Definition..." selection as you would for any other automated calibration. Select this "PPC4 via PG, PPCPR" as the DUT. When COMPASS initializes the test it will flag a warning message that two or more devices are using the same COM port. This is okay, and press OK to continue.

COMPASS is used to automate the test and to collect data.  If desired, CalTool for RPTs (separate software program) can be used to calculate new PA and PM values for the Q-RPT (or utility sensor) and adjust them in the PPC. If you are calibrating a utility sensor and just need to make an offset adjustment you can probably easily determine what the change needs to be and adjust the PA value only.


If the PPCx has two transducers or multiple ranges (ie: H1, H2, H3, etc), then it is recommended to make a copy of the DUT Definition and modify the Record Label name to show that it's used for a different pressure range.  Then, under the Output tab, the Min and Max pressure values should be edited to reflect the range to be calibrated.  Repeat this process for each range used by the PPCx.




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