Pressure Systems 98RK-1 user manual Span Calibration Valve Control

Pressure Systems, Inc. 98RK-1 & 9816 User’s Manual©

stored back into the transducer’s nonvolatile memory afterwards. In other cases, the user’s application may not require periodic span 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 Calculate and Set Gains ('Z') command, the module will perform the Span adjustment calibration, and then update the gain coefficients in its volatile memory. It will subsequently use the newly calculated gain terms for subsequent engineering-unit calculations.

When using the Calculate and Set Gain ('Z') command, only the Note local variables in the module’s volatile main memory (RAM) are

changed. Refer to Section 4.5 if it is desired to also store these new gain coefficients in transducer nonvolatile memory.

4.3.1.Span Calibration Valve Control

Before executing a Span adjustment (Calculate and Set Gains ('Z') command), Model 9816 modules should have their calibration manifold valve placed in the proper position. For single pressure range units, the CAL position should be used since the span calibration pressure can be applied between the CAL 1-8and CAL REF ports. Since the module will not attempt to shift this valve automatically, as it does for Re-zero adjustment, it should be placed in the desired position manually with the Set Operating Options ('w') command (option indexes = 0C and 12).

When span calibrating Model 9816 modules with multiple ranges installed, the CAL port may be used to apply pressure to all transducers only if the specified proof pressure is not exceeded on any channel. If the application of a specific span pressure exceeds the proof pressure rating of any other transducer contained within the same scanner, the calibration pressures must be applied to the RUN side pneumatic input ports. Since the calibration command ('Z') has a channel selection bit map parameter allowing it to calibrate only the desired pressure channels, the RUN port is a viable option for supplying the calibration pressures.

Pneumatic Connector Assignment on Rear Input Panel of the 98RK-1

Connection

Pressure Scanner Range Input

Cal 1	User defined
Cal 2	10" W.C.; 20" W.C.; ±1 psid, ±1.5 psid
Cal 3	±2.5; ±5 psid
Cal 4	±10; ±15 psid, ±20 psid, ±25 psid
Cal 5	±30; ±45; ±50 psid
Cal 6	±75 psid, ±100 psid
Cal 7	+ 150; 200; 250; 300 psid
Cal 8	500 psid, 600 psid, 650 psid, 750 psid, 850
	psid

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