Siemens LMV5 Series Technical Instructions page 200

Technical Instructions
Document No. LV5‐1000
As previously mentioned, the QGO20 is only capable of measuring %O
situ oxygen sensor, not needing any type of water trap, desiccant, or filter. In‐situ sensors typically have
a much shorter delay time (Tau time) and require much less maintenance than other types of O
sensors.
Most hand‐held combustion analyzers measure %O
from the %O wet measured by the QGO20 sensor.
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Figure 6‐11 shows these approximate differences along with the raw milli‐volt signal from the Zirconium
oxide O cell. As one would expect, the raw milli‐volt signal varies with sensor temperature, but this
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variance is compensated by the PLL52 module so the LMV52 is fed an accurate, compensated O
%O Wet
2
0.1
1
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
6.5
7
7.5
8
8.5
9
10
11
12
13
14
15
16
17
18
19
20
20.9
Figure 6‐11: O
Section 6 Page 28 SCC Inc.
dry, and therefore will be considerably different
2
%O Dry Output Voltage
2
(Natural Gas) (mV) @ 1292 F
0.1
1.3
1.9
2.5
3.1
3.8
4.4
5.0
5.6
6.3
6.9
7.5
8.1
8.7
9.3
9.9
10.6
11.2
Wet, O Dry, and Nernst Voltage Conversion (approximate)
2 2
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wet. This is true since it is an in‐
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Output Voltage
(mV) @ 1320 F
111.79 113.59
63.61 64.63
55.12 56.01
49.10 49.90
44.43 45.15
40.62 41.27
37.39 38.00
34.60 35.16
32.13 32.65
29.93 30.41
27.93 28.39
26.11 26.54
24.44 24.83
22.89 23.26
21.44 21.79
20.09 20.42
18.83 19.13
17.63 17.91
15.43 15.67
13.43 13.65
11.61 11.80
9.94 10.10
8.38 8.52
6.94 7.05
5.59 5.68
4.32 4.39
3.13 3.18
1.99 2.03
0.92 0.94
0.00 0.00
LMV Series
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value.
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