Teledyne LXT-280 - Manual (Page 44)

Calibration Correction LXT-280
Teledyne Analytical Instruments 34
7. To calculate the compensated dissolved oxygen value, multiply
the ppm oxygen value (recorded from Table 5-1) by the two
correction factors (recorded from Tables 5-2 and 5-3). This value
is the dissolved oxygen value of air or an air-saturated sample
corrected for temperature, relative humidity and elevation.
8. After the corrected value has been calculated, but before the
value has been entered in the instrument, the temperature
element in the sensor must have time to stabilize. The
temperature of the sensor must be the same as the temperature
used in selecting the ppm value in Table 5-1. If the temperature
of the sensor and value used from Table 5-1 are not the same, an
error will be introduced into the calibration.
5.2 Salinity Correction
When seawater, brine or brackish samples or processes are being
measured, a special salinity correction table is required. The correction
factor is multiplied by the corrected dissolved oxygen value as
determined in Section 5.1. Table 5-4 summarizes the salinity correction
factors at a barometric pressure of 29.92" Hg (760 mm Hg).
Table 5-4: Salinity Correction Factor
Dissolved Oxygen Salinity Correction Factors
at a Barometric Pressure of 29.92" Hg (760 mm Hg)
Salinity in
ppt
Correction
Factor
Salinity in
ppt
Correction
Factor
0 1.00 20 0.81
2 0.98 22 0.80
4 0.96 24 0.78
6 0.94 26 0.76
8 0.92 28 0.75
10 0.90 30 0.73
12 0.88 35 0.70
14 0.86 40 0.66
16 0.85 45 0.63
18 0.83 50 0.60