
Teledyne API Model 300M CO Analyzer Instruction Manual, 04033, Rev. A
3.6Remote Zero/Span Check or Adjustment (Contact Closure)
In addition to adjustment via the front panel buttons, the analyzer can be adjusted by means of two contact closures called EXT_ZERO_CAL and EXT_SPAN_CAL. (See Figure
Also, if a positive transition occurs on either signal while the M300M is in zero, span check or hold off, it will immediately switch to the specified mode. For example, if the analyzer is in zero check and a positive transition is detected on EXT_SPAN_CAL, then the instrument will immediately go into span check. To perform a zero check followed by a span check, first generate a positive transition on EXT_ZERO_CAL, and then when you want to do the span check, generate a positive transition on EXT_SPAN_CAL.
The remote calibration signals may be activated in any sequence, providing a virtually unlimited number of calibration types.
Remote adjustment is similar to automatic Z/S checking in that if dynamic calibration is enabled, the internal CO formulas will be modified following calibration. To enable or disable adjustment, press
NOTE
Teledyne API recommends that contact closures remain closed at
least
10 minutes to allow for an accurate average zero or span value
to be established.
NOTE
Remote zero and span adjustment alter the formulas used to compute the carbon monoxide readings if DYN ZERO or DYN SPAN are enabled.