Hanna Instruments HI 98186 User Manual
Page 14
14
The HI 98186 meter contains a built-in barometer, and it is able to automati-
cally compensate for changes in barometric pressure. If another pressure value
than the barometer’s reading is to be used, then the manual pressure feature
must be enabled from the SETUP menu (see page 33), and afterwards the
pressure value can be set using the ARROW keys.
The table below contains a conversion altitude (m) to pressure (mmHg) for the
altitude values from the previous table.
DO MEASUREMENTS
Make sure the probe’s protective cap has been removed.
In order to take accurate dissolved oxygen measurements make sure that the
instrument has been calibrated (see page 27 for details).
Press RANGE to access the DO measure screen. If necessary press MODE to
change the measuring unit.
Immerse the tip of the probe into the sample to be tested. Allow approxi-
mately one minute for the reading to stabilize (hourglass symbol turns off).
On the screen are displayed:
•
Dissolved Oxygen reading in the selected unit (% saturation or mg/L)
•
Temperature reading in the selected unit (°C or °F)
•
Pressure reading in the selected unit (mmHg, inHg, atm, psi, kPa, mbar).
If the Manual Pressure option is enabled ( displayed in front of the pressure
value) the pressure value can be changed using the ARROW keys.
For accurate dissolved oxygen measurements, a water movement of
0.3 m/s is required. This is to ensure that the oxygen-depleted membrane
surface is constantly replenished. A moving stream will provide adequate
circulation.
e
d
ut
itl
A
)
m
(
0
0
0
3
0
0
6
0
0
9
0
0
2
1
0
0
5
1
0
0
8
1
0
0
1
2
0
0
4
2
0
0
7
2
0
0
0
3
0
0
3
3
0
0
6
3
0
0
9
3
0
0
0
4
er
us
se
r
P
)g
H
m
m
(
0
6
7
2
3
7
5
0
7
9
7
6
4
5
6
0
3
6
7
0
6
4
8
5
3
6
5
2
4
5
2
2
5
3
0
5
4
8
4
7
6
4
1
6
4