Honeywell Sensepoint XCD Technical Manual page 75

Sensepoint XCD Technical Manual
Cross Calibration Flammable Gas Detector
Note: Not a scope for performance approval
For greater accuracy, a catalytic gas detector should be calibrated using a certified gas/air mixture equal
to 50 % LEL of the actual target gas intended to be monitored.
However, it is not always practical to obtain every detectable type of hydrocarbon gas in a calibration-
ready, certified and verifiable form. Therefore, it is possible to carry out a 'cross calibration' using another
hydrocarbon gas/air mixture.
When the Sensepoint XCD Combustible LEL sensor is to be calibrated with a gas which is different to
the gas or vapour to be detected, the following cross calibration procedure may be followed:
Where the user calibrates any sensor using a different gas, responsibility for identifying and
recording calibration rests with the user. Refer to the local regulations where appropriate.
Note: Table 10 lists a selection of hydrocarbon compounds and states a reference figure or 'Star
Rating' according to the reaction they produce in relation to other hydrocarbons. An eight-star (8*) gas
produces the highest output, while a one-star (1*) gas produces the lowest output.
CAUTION
No.
1 Acetone
2 Ammonia
3 Benzene
4 Butanone
5
6 Butyl acetate
7 Butyl acrylate
8 Cyclohexane
9 Cyclohexanone
10 Diethyl ether
11
12 Ethanol
13 Ethyl acetate
14 Ethylene
15 Heptane
16 Hexane
17 Hydrogen
18 Methane
19 Methanol
20
21
22 Pentane
23 Propane
24 Propan-2-ol
25 Styrene
26 Tetra hydrafuran
27 Toluene
28 Triethylamine
29
Table 10 Star Rating of Gases
75
SPXCDHMANEN Issue 15
Gas Star Rating
Butane
Ethane
MIBK
Octane
Xylene
4*
7*
3*
3*
4*
1*
1*
3*
<1*
4*
6*
5*
3*
5*
3*
3*
6*
6*
5*
3*
3*
3*
5*
4*
2*
4*
3*
3*
2*