Hummingbird Communications Paracube Micro, Instruction Manual

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30 of 35 01115009A _9
Paracube
®
Micro – Instruction Manual
Appendix 7.5 Sample Gas Cross Sensitivity Guide
The example below demonstrates how the effect of background gases may be
calculated.
Sample gas composition at 50°C
10% CO
2
5% CO
5% HCCH
78% N
2
Using the table below, the correct zero offset can be calculated:
CO
2
-0.29 x 10
-2
x 10 = -0.029
CO 0.07 x 10
-2
x 5 = 0.004
HCCH -0.28 x 10
-2
x 5 = 0.014
N
2
0.00 x 10
-2
x 78 = 0.000
Net background effect = -0.039
This offset may be removed during calibration by setting the zero point to +0.039% O
2
.
Zero Error / % of interfering gas
Gas Formula
χ
M x 10-6
20
°
C
x 0.01%
50
°
C
x 0.01%
60
°
C
x 0.01%
Acetaldehyde CH
2
CHO -22.70 -0.31 -0.34 -0.35
Acetic Acid CH
3
CO
2
H -31.50 -0.56 -0.62 -0.64
Acetone CH
3
COCH
3
-33.70 -0.63 -0.69 -0.71
Acetylene HCCH -20.80 -0.25 -0.28 -0.29
Acrylonitrile CH
2
=CHCN -24.10 -0.35 -0.39 -0.40
Allyl Alcohol CH
2
CHCH
2
OH -36.70 -0.71 -0.79 -0.81
Ammonia NH
3
-18.00 -0.17 -0.19 -0.20
Argon Ar -19.60 -0.22 -0.24 -0.25
Benzene C
6
H
6
-54.84 -1.24 -1.36 -1.41
Bromine Br
2
-73.50 -1.78 -1.96 -2.02
1,2 Butadiene C
4
H
6
-35.60 -0.68 -0.75 -0.77
1,3 Butadiene C
4
H
6
-30.60 -0.54 -0.59 -0.61
N-Butane C
4
H
10
-50.30 -1.11 -1.22 -1.26
Iso-Butane (CH
3
)
2
CHCH
2
-51.70 -1.15 -1.26 -1.30
N-Butyl Acetate CH
3
COOC
4
H
9
-77.50 -1.89 -2.09 -2.15
Iso-Butylene (CH
3
)
2
CH=CH
2
-44.40 -0.94 -1.03 -1.06
Carbon Dioxide CO
2
-21.00 -0.26 -0.29 -0.30
Carbon Disulphide CS
2
-42.20 -0.87 -0.96 -0.99
Carbon Monoxide CO -9.80 0.06 0.07 0.07
Carbon Tetrachloride CCl
4
-66.60 -1.58 -1.74 -1.79