Calibrating Aim-Mv Input Channels - Honeywell Touchpoint Pro Technical Handbook

CALIBRATING GAS SENSORS

8.2 Calibrating AIM-mV Input Channels

Touchpoint Pro supports routine calibration of mV sensors. TPPR can be programmed to display calibration reminders at
calibration intervals, e.g. annually or every six months.
It is compulsory to calibrate the sensor when a channel has been newly commissioned, when the sensor bead current has
been changed, or if the system configuration has been deleted.
TPPR warns when the output from a sensor reaches 50% of its initial value and should be replaced. The First Span
calibration option is used to record the initial output level of a new sensor.
Note: The maximum allowable span signal is 300mV for 100% FSD. This figure is scaled by the Span Gas Concentration
that has been entered i.e. 50% span gas concentration limits the maximum mV reading to 150mV.
Note: TPPR mV Analogue Input channels (AIM-mV) will remain in the Inhibit state until they are calibrated.
Note: Zero and Span may be calibrated independently. When replacing a sensor, both Zero and First Span calibrations shall
be carried out.
Channel calibration is compulsory after changing the bead current (or catalytic sensor) of an AIM mV channel, and
Disable or inhibit any operations or actions that may result from gas readings before starting this test.
8.2.1 First Span
TPPR has the option of carrying out First Span or Span. Select First Span when calibrating a new or replacement sensor
for the first time, and Span for all calibrations thereafter.
The signal voltage from catalytic sensors reduces over time. Regular recalibration is required to make allowance for
This slow change is monitored by TPPR and is used to give the sensor life expired warning when the Span value is
When installing a new sensor the TPPR will use its default value if First Span is not used, which may result in a
Always use the same type and concentration of Span Gas to ensure accurate and consistent testing and calibration.
8.2.2 Calibration Procedure
To calibrate a mV input channel follow the procedure below, in conjunction with the relevant sensor manual.
The channel must be inhibited before calibration is allowed. If not already automatically inhibited, the channel can be
inhibited from the Inputs icon popup menu or the Gas Calibration screen.
1. Login as an Administrator or Engineer
2. From the System Status screen select the Inputs icon then select the channel to be calibrated
3. Select Inhibit from the popup menu, if not already inhibited.
4. Select Gas Calibration from the popup menu
Part. No. 2400M2501_6
CAUTION
the channel stays in Inhibit until this is done.
these changes.
≤50 % of the First Span value.
CAUTION
premature life expired warning or no warning at all!
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