Calibration 20; Zero And Span Calibration For Mpd Sensors With Xnx Universal Transmitter - Honeywell MPD Series Operating Manual

7 Calibration
CAUTION
The calibration procedure should only be performed by qualified personnel.
NOTe:
Honeywell Analytics recommends that the maximum calibration interval
be 6 months or in accordance with customer site procedures, whichever
is sooner to assure the highest level of safety. Correct operation of each
sensor/detector should be confirmed with test gas of known concentration
before each use.
71 Zero and Span Calibration for MPD Sensors with XNX Universal
Transmitter
CAUTION
Before initial calibration allow the detector to stabilize for 30 minutes after
applying power. When in zero and span calibration mode the current output from
the detector is inhibited (e.g. default 2mA) to avoid false alarms.
Extended or frequent exposure to elevated concentrations of combustible gases
may affect sensor sensitivity. Verify sensor performance by frequent calibration.
This section describes how to calibrate MPD sensors fitted to the XNX Universal
Transmitter.
The calibration adjustments are made on the XNX's display and gassing is performed
at the sensor (this may be locally or remotely located).
The following equipment is required:
• Sample/Calibration Gas Flow Adaptor (Part No: 1226A0411)
• Test gas
• Regulator
NOTe
Zero gas and Span gas should be at roughly the same humidity levels to
avoid erroneous cell responses.
1. At the MPD, remove the Weatherproof Cap if equipped.
2. Fit the Flow Adaptor onto the MPD.
Reverse the cap removal procedure. The following diagram shows the Flow Adaptor
accessory fitted to the MPD.
20
Figure 10. Flow Adaptor
MPD Operating Manual