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.
