Pressure Systems NetScanner 9116, Руководство пользователя

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Pressure Systems, Inc. Model 9116 User’s Manual
Page 94 www.PressureSystems.com
4.2.2 Re-zero Calibration Summary
Following is a simple, step-by-step procedure for executing a Re-zero calibration of a Model
9116 Intelligent Pressure Scanner. Optional commands are shown within brackets [ ].
Description Model 9116 Command
Disable automatic valve shifting after module power up.
Ensure valves in
RUN/CAL mode (default)
[w0B01]
[w1200]
… normal data acquisition
Apply 0.0 psi differential to the module CAL and CAL REF
inputs.
Place the module calibration manifolds into the CAL position
[if w0B01 command executed in Step 1]
w0C01
Delay for settling of pneumatic inputs
Verify that measured data reads near expected zero value [rFFFF0]
Instruct module to calculate new offset coefficients for all 16
channels of Model 9116
hFFFF
Place calibration manifold back into the RUN position [if
w0B01 command executed in Step 1]
[w0C00]
Store new offset coefficients to transducer nonvolatile
memory
[w08]
… continue normal data acquisition
4.3 Span Calibration
For improved accuracy,
Model 9116 Intelligent Pressure Scanners are capable of
independently performing a transducer calibration function, referred to as Span adjustment (or
simply Span Cal). Actually, there is a provision to supply any suitable “upscale” pressure (e.g.,
actual transducer full-scale) during such a calibration adjustment. The
Span adjustment
calibration will result in a recalculated “gain” coefficient for each channel being calibrated, to
compensate for any transducer or module gain errors. For best results, a Re-zero calibration
should be performed before performing a span calibration. Also, note that a new and improved
Multi-Point Calibration function exists. This function integrates the separate calibration
functions (for Re-zero and Span adjustment described in Section 4.2 and this section) into a
single function that adjusts both “offset” and “gain” coefficients at the same time, using two or
more calibration points. Details of using this improved calibration function are described in
Section 4.4.