Hanna Instruments HI 9146-04 - Manual (Page 3)

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FUNCTIONAL DESCRIPTION - PROBE
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1. D.O. Probe
2. Protective Cap
3. Watertight Shielded
Cable
4. P o l y p r o p y l e n e
Probe Body
5. Temperature Sen-
sor
6. O-Ring Seal
7. AgCl Anode (sensor
element)
8. Platinum Cathode
(sensor element)
9. Oxygen Permeable
Teflon Membrane
10. Membrane Protec-
tive Cap
FUNCTIONAL DESCRIPTION - METER
1) Battery Compartment
2) Probe Connector
3) Liquid Crystal Display
4) ON/OFF key
5) CAL key (to enter/exit calibration mode)
6) FACTOR key (to select altitude F1 and
salinity F2)
7) UP and DOWN arrow keys (to select F1
and F2 levels)
8) HOLD key (to freeze displayed value)
9) RANGE key (to select ppm or % of
saturation)
10) Power socket for 12 Vdc adapter
19) LOW BAT indicator
20) SAMPLE indicator (to indicate measure-
ment mode)
21) F1 indicator (altitude factor)
22) F2 indicator (salinity factor)
23) % or ppm mode indicator
24) Temperature and factor display
Salinity compensation in water allows
determination of mg/L of dissolved oxygen in
salty waters and the altitude compensation
readjusts for the altitude variance.
Four 1.5V AA alkaline batteries provide power
and make the instrument completely portable.
HI 9146 is also designed to be used with a battery
recharger or a 12 Vdc power supply. A 12 Vdc
input jack is incorporated into the housing.
A microprocessor ensures an accurate and
rapid calibration and measurement. The case
rugged and water-resistant for maximum
protection in the field as well as in the laboratory.
The dissolved oxygen probe has a membrane
covering the polarographic sensor elements
and a built-in thermistor for temperature
measurement and compensation. The thin
permeable membrane isolates the sensor
elements from the testing solution, but allows
oxygen to enter. When a voltage is applied
across the sensor, oxygen that passes through
the membrane causes a current to flow from
which the oxygen concentration is determined.