Altitude and salinity compensation – Hanna Instruments HI 9142 User Manual
Page 14
12
13
SALINITY COMPENSATION
The table below shows the influence of salt in the measurement
of oxygen.
In
HI 9142 all the readouts are referred to 0 g/L of salinity value.
In fact, salinity affects D.O. concentration decreasing its value.
For your reference the table below reports the oxygen solubility
at various temperatures and salinity. From the table you can
calculate the quantity to be subtracted to correct your reading.
ALTITUDE AND SALINITY COMPENSATION
If the sample contains salts or if you are performing the
measurements at a different altitude than sea level, the readout
values must be corrected, taking into account the lower degree of
oxygen solubility.
ALTITUDE COMPENSATION
All the readouts are referred at sea level, thus the displayed
measurements are higher than the actual values. In fact, altitude
affects D.O. concentration decreasing its value. The following
table reports the oxygen solubility at various temperatures and
altitudes, based on sea level barometric pressure of 760 mm Hg.
This gives an idea of the error that can be introduced at different
altitudes and allows you to calculate the quantity to be subtracted
to correct your reading.
C
°
l
e
v
e
L
a
e
S
e
v
o
b
a
s
r
e
t
e
M
,
e
d
u
ti
tl
A
F
°
m
0
m
0
0
3
m
0
0
6
m
0
0
9
m
0
0
2
1
m
0
0
5
1
m
0
0
8
1
0
6
.
4
1
1
.
4
1
6
.
3
1
2
.
3
1
7
.
2
1
3
.
2
1
8
.
1
1
0
.
2
3
2
8
.
3
1
3
.
3
1
9
.
2
1
4
.
2
1
0
.
2
1
6
.
1
1
2
.
1
1
6
.
5
3
4
1
.
3
1
7
.
2
1
2
.
2
1
9
.
1
1
4
.
1
1
0
.
1
1
6
.
0
1
2
.
9
3
6
4
.
2
1
0
.
2
1
6
.
1
1
2
.
1
1
8
.
0
1
4
.
0
1
1
.
0
1
8
.
2
4
8
8
.
1
1
4
.
1
1
0
.
1
1
6
.
0
1
3
.
0
1
9
.
9
6
.
9
4
.
6
4
0
1
3
.
1
1
9
.
0
1
5
.
0
1
2
.
0
1
8
.
9
5
.
9
2
.
9
0
.
0
5
2
1
8
.
0
1
4
.
0
1
1
.
0
1
7
.
9
4
.
9
1
.
9
8
.
8
6
.
3
5
4
1
3
.
0
1
9
.
9
6
.
9
3
.
9
0
.
9
7
.
8
3
.
8
2
.
7
5
6
1
9
.
9
7
.
9
2
.
9
9
.
8
6
.
8
3
.
8
0
.
8
8
.
0
6
8
1
5
.
9
2
.
9
7
.
8
6
.
8
3
.
8
0
.
8
7
.
7
4
.
4
6
0
2
1
.
9
8
.
8
5
.
8
2
.
8
9
.
7
7
.
7
4
.
7
0
.
8
6
2
2
7
.
8
4
.
8
1
.
8
8
.
7
7
.
7
3
.
7
1
.
7
6
.
1
7
4
2
4
.
8
1
.
8
8
.
7
5
.
7
3
.
7
1
.
7
8
.
6
2
.
5
7
6
2
1
.
8
8
.
7
5
.
7
3
.
7
0
.
7
8
.
6
6
.
6
8
.
8
7
8
2
8
.
7
5
.
7
3
.
7
0
.
7
8
.
6
6
.
6
3
.
6
4
.
2
8
0
3
5
.
7
2
.
7
0
.
7
8
.
6
5
.
6
3
.
6
1
.
6
0
.
6
8
2
3
3
.
7
1
.
7
8
.
6
6
.
6
4
.
6
1
.
6
9
.
5
6
.
9
8
4
3
1
.
7
9
.
6
6
.
6
4
.
6
2
.
6
0
.
6
8
.
5
2
.
3
9
6
3
8
.
6
6
.
6
3
.
6
1
.
6
9
.
5
7
.
5
5
.
5
8
.
6
9
8
3
6
.
6
4
.
6
2
.
6
9
.
5
7
.
5
6
.
5
4
.
5
4
.
0
0
1
0
4
4
.
6
2
.
6
0
.
6
8
.
5
6
.
5
4
.
5
2
.
5
4
.
4
0
1
C
°
l
e
v
e
L
a
e
S
t
a
)
L
/
g
(
y
ti
n
il
a
S
F
°
L
/
g
0
L
/
g
0
1
L
/
g
0
2
L
/
g
0
3
L
/
g
5
3
0
1
3
.
1
1
6
.
0
1
9
.
9
3
.
9
0
.
9
0
.
0
5
2
1
8
.
0
1
1
.
0
1
5
.
9
9
.
8
6
.
8
6
.
3
5
4
1
3
.
0
1
7
.
9
1
.
9
6
.
8
3
.
8
2
.
7
5
6
1
9
.
9
3
.
9
7
.
8
2
.
8
0
.
8
8
.
0
6
8
1
5
.
9
9
.
8
4
.
8
9
.
7
6
.
7
4
.
4
6
0
2
1
.
9
5
.
8
0
.
8
6
.
7
4
.
7
0
.
8
6
2
2
7
.
8
2
.
8
8
.
7
3
.
7
1
.
7
6
.
1
7
4
2
4
.
8
9
.
7
5
.
7
1
.
7
9
.
6
2
.
5
7
6
2
1
.
8
6
.
7
2
.
7
8
.
6
6
.
6
8
.
8
7
8
2
8
.
7
4
.
7
0
.
7
6
.
6
4
.
6
4
.
2
8