Honeywell Sensepoint XCD, Technical Manual

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Sensepoint XCD Technical Manual SPXCDHMANEN Issue 2
26
10 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;
1. 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 LPM, OR, to shelter the
weather protection from the wind.
2. A full gas calibration of the sensor as described in the following section, using ONLY the
Sensepoint XCD Gassing Cap (Part No.: S3KCAL).
10.1 Zeroing and span calibration
To calibrate the detector, use an appropriate span gas cylinder, constant flow regulator
AND the Sensepoint XCD Gassing Cap (see section 4.7). 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
Flammable IR 0.4 to 0.6
CO
2
IR 0.4 to 0.6
A compressed air cylinder (20.9%Vol oxygen) should be used to perform the zero
calibration if the area where the detector is located contains any residual amount of the
target gas. If no residual gas is present then the background air can be used to perform
the zero calibration. Contact your Honeywell Analytics representative for details of suitable
calibration kits.
To calibrate the detector follow the procedure below.
Note: the Oxygen sensor does not require a zeroing procedure. Background air (20.9%Vol
oxygen) can be used to span the oxygen sensor in place of a compressed air cylinder
(20.9%Vol oxygen). For oxygen sensors only do parts 1-4, 12, 13 (if compressed air
cylinder is used), 14-17 and 22 of the procedure below.
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 2mA) 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 section 10.1.2 before conducting zero and span
calibration.