Teledyne API Model 200A NOX Analyzer Instruction Manual, 02246, Rev. G, DCN 5247
7.7 Use of Zero/Span Valves or IZS with Remote Contact Closure
The Zero/Span valve or IZS options can be operated using Remote Contact Closures provided on
the rear panel. See Table 2-2-2 for connector location and pinout. When the contacts are closed,
the analyzer will switch to zero or span mode. The contacts must remain closed for at least 1
second, and will remain in zero or span mode as long as the contacts are closed. If Dynamic
Zero/Span is enabled, the calibration is adjusted at the end of the zero or span time, otherwise
zero or span is just checked, not adjusted.
In order to do another remote check, both contact closures should be held open for at least 1
second, then may be set again. Table 7-7-10 shows what type of check is performed based on the
settings of the two contact closures.
Table 7-7-10: IZS or Z/S Valves Modes with Remote Contact Closure
Ext Zero CC Ext Span CC Operation
Contact Open Contact Open State when in SAMPLE mode, normal monitoring
Contact Open Contact Closed Span check or calibrate*
Contact Closed Contact Open Zero check or calibrate*
* Calibrate only if Dynamic Calibration is enabled.
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