Honeywell Sensepoint XCD - Response Check and Calibration; Zeroing and Span Calibration

Sensepoint XCD Technical Manual SPXCDHMANEN Issue 15
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9. Response Check and Calibration
It is recommended to periodically carry out a gas response check on the Sensepoint XCD to ensure
correct operation. This may be done in two ways;
A simple Response Check often referred to as a ‘BUMP TEST’ is a test using calibration gas applied to
the sensor via the nozzle of the Weather Protection or using the Sensepoint XCD Gassing Cap.
If a BUMP TEST is done via the Weather Protection nozzle it may be necessary in windy conditions to
increase the flow rate of the test gas by a further 1 l/min, OR, to shelter the weather protection from the
wind.
A full gas calibration of the sensor as described in the following section, using ONLY the Sensepoint
XCD Gassing Cap (Part No.: S3KCAL).
Zeroing and span calibration
To calibrate the detector, use an appropriate span gas cylinder, constant flow regulator AND the
Sensepoint XCD Gassing Cap (see chapter 3.2). The flow rates used for calibration gas are as follows:
Gas Type
Flow rate (l/min)
Air or N
2
for Zero
0.5 to 1.0
Flammable CAT
1 to 1.5
O
2
0.5 to 1.0
H
2
S
0.5 to 1.0
CO
0.5 to 1.0
H
2
0.5 to 1.0
NO
2
0.5 to 1.0
Flammable IR
0.4 to 0.6
CO
2
IR
0.4 to 0.6
WARNING
As some calibration gases may be hazardous, ensure that outlets from gassing accessories
exhaust safely.
CAUTION
Before initial calibration allow the detector to stabilize for 30 minutes after applying power.
When in zeroing and span calibration mode the current output from the detector is
inhibited (default 2 mA) to avoid false alarms. For Flammable gas calibration use a
calibration gas concentration of between 25 % LEL and 75 % LEL to ensure that the
required accuracy can be attained. For Hydrogen Sulfide type sensors refer to chapter 9.2
before conducting zero and span calibration. For toxic sensors use a calibration gas of
approximately 50 % FSD.