Filter
Top Products
Appendices
January 2009 UDA2182 Universal Dual Analyzer Product Manual 225
15.12 Appendix K – Percent Saturation Readout
In some special applications, it is desirable to read out in percent saturation rather than concentration. These are usually in non-
aqueous solutions where the normal temperature compensation of the Series UDA2182 Analyzer for the solubility of air/oxygen
in water does not apply. The percent saturation readout disables this solubility part of the temperature compensation. The
readout is 100% when measuring in air or in a solution saturated with air, regardless of the temperature. Thus an air calibration
will always produce approximately a 100% saturation readout. With this readout, salinity should be left at zero since the normal
salinity correction also does not apply to non-aqueous media.
When percent saturation readout is selected, the on-line displays read in percent saturation, however, all the dissolved oxygen
settings in the Analyzer remain in concentration units (ppm or ppb). Therefore, percent saturation alarms, output, etc. Should be
used only if the process temperature is nearly constant.
For example, assume it is desired to have an alarm setpoint at 75% saturation while operating at 20°C. The corresponding
setpoint is the 0.75 x 9.07 = 6.80 ppm.
Table 15-2 Dissolved Oxygen Solubility vs. Temperature
(From Standard Methods for the Examination of Water and Wastewater)
Sample
Temperature
(°C)
Solubility
(ppm, mg/L)
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
14.60
14.19
13.81
13.44
13.09
12.75
12.43
12.12
11.83
11.55
11.27
11.01
10.76
10.52
10.29
10.07
9.85
9.65
9.45
9.26
9.07
8.90
8.72
8.56
8.40
8.24
8.09
7.95
7.81
7.67
7.54
7.41
7.28
7.16
7.05
6.93
6.82
6.71
6.61
6.51
6.41
6.31
6.22
6.13
6.04
5.95
5.86
5.78
5.70
5.62
5.54