13
(Temperature in Kelvin)
Figure 1. The species distribution of H2S, HS and S2- as a function of
pH.
As H
2
S sensors are sensitive to temperature, it is necessary to
perform calibration and measurements at the same temperature .
Please note that, in contrast to oxygen, the relationship between
salinity, temperature and solubility is not well known and
therefore not tabled for sulfide gas
c
alibration
in
the
laboratory
Calibration must be performed after the sensor signal has
stabilized during pre-polarization . The H
2
S microsensor responds
linearly over a certain range (e .g . 0-300 µM), above which the slope
of the response curve decreases, but the response and resolution
above the linear range may be sufficiently good for reliable
measurements . We suggest that you establish the linear range by
making a coarse calibration in the entire concentration range of
interest . If measurements of concentrations above the linear range
are needed, a calibration with sufficient resolution has to be made
in the non-linear range, whilst a 3-point calibration is sufficient in
the linear range .
0
2
4
6
8
10
12
14
0
25
50
75
100
Species
%
pH
H
2
S
HS
-
S
-
