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Measurement Specialties Inc. NetScanner System (9016, 9021, & 9022) User’s Manual
4 - 10
4.4 Integrated Multi-Point Calibration Adjustment
NetScanner
System Intelligent Pressure Scanners may have their accuracy enhanced by regular
application of one or both of the individual Re-zero and Span calibration adjustment functions
already described in Sections 4.2 and 4.3. For users who have installed scanner firmware
version 2.24 or later, an integrated and more comprehensive Multi-Point Calibration function
may be used instead to adjust the same offset and gain coefficients for a module’s channels. This
function also provides for supplying additional calibration points, which is particularly useful
when it is desired to fit the adjustment data to the entire negative and positive range of the module.
This integrated calibration adjustment function is fully described in this section. It is
implemented by four (4) sub-commands of the ‘C’ command. Since this function combines the
functions of the Re-zero and Span calibration adjustments (using the ‘h and Z’ commands) it is
recommended that you read the information of Section 4.2 and 4.3 before attempting to perform
this multi-point calibration.
It is recommended that a Multi-Point Calibration adjustment be performed whenever new
transducers are installed in your module. In such cases, the new zero and gain coefficients that
result should always be restored into the transducer’s non-volatile memory afterwards. In some
cases, the user’s application may not require such a comprehensive adjustment as the other
factory-determined pressure/temperature coefficients (stored permanently inside each transducer)
are extremely stable. Only an occasional Re-zero adjustment may be all that is necessary.
When instructed to execute a particular sequence of sub-commands of the Configure Multi-Point
Calibration (‘C’) command, the module will perform the various stages of the Multi-Point
Calibration adjustment calibration function, and then update both the offset and gain coefficients
in the module’s volatile (e.g., RAM) memory. The module will use this newly calculated data
term for all subsequent engineering-unit calculations.
4.4.1. Multi-Point Calibration Valve Control
Before executing a Multi-Point Calibration adjustment (using various forms of the
Configure/Control Multi-Point Calibration (‘C’) command), Model 9016 modules should have
their calibration valve placed in the proper position. For modules with only one common
pressure range for its transducers, the CAL position should be used since the span calibration
pressure can be applied between the CAL and CAL REF ports (see Section 4.3.1 for more
information on these ports). Since the module will not attempt to shift this valve automatically,
NOTE: When using the Configure/Control Multi-Point Calibration (C’) command,
only the local variables in the module’s volatile main memory (RAM) are changed.
Refer to Section 4.6 if it is desired to also store these new offset and gain coefficients
in transducer non-volatile memory.
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