Elma 795
UK 38
v. 290817
06-09-2016 10:40:26
8. DO ( Dissolved Oxygen ) MEASURING and CALIBRATION PROCEDURE
8-1
Dissolved Oxygen measurement
1.
Connect the Probe (optional, DOPB-11), (8-1, Fig.5) into the
”
DO
”
Socket (3-14, Fig.1)
2.
Use the "
Function”
Button, step to the ”
do
” function. See pkt. 4.
1.
a.
Immersed the probe to a depth at least 10 cm of the measured liquid in
order for the probe to be influenced by the temperature & automatic
temperature compensation to take place.
b.
As for the thermal equilibrium to occur between the probe & the measurement
sample must be allowed to pass, which usually amounts to a few minutes if the Temp. difference
between the two is only several Celsius degrees.
2.
a
. In order to measure the dissolved oxygen content in any given liquid, it is sufficient to immerse the
tip of the probe in the solution, making sure that velocity of the liquid coming into contact with the
probe is at least 0.2 - 0.3 m/s or to shake the probe.
b.
During laboratory measurements, the use of a magnetic agitator to ensure a certain velocity in the
fluid is recommended. In this way, errors due to the diffusion of the oxygen present in the air in the
solution are reduced to a minimum.
3.
Display will show the Dissolved Oxygen values (mg/L) and Temp. value of the measured solution.
4.
Rinsed the probe accurately with normal tap water after each series of measurement.
Oxygen in the air
Use the "
Function
” Button, step to the”
O2
” function. See pkt.4
The Display unit will show "%O2", and show the air Oxygen value for reference
8-2 Calibration
1.
Connect the Probe (optional, DOPB-11), (8-
1, Fig.5) into the ”
DO
” Socket (3-14, Fig.1)
2.
Use the "
Function”
Button, step to the
”
O2
” function. See pkt. 4.
3.
Wait for. 5 minutes at least until the display reading values become stable & no fluctuation.
4.
Use two fingers to press the "▲ Button" (3-5, Fig 1) and "▼ Button" (3-6, Fig. 1) at the same time.
Until the Display shows
“
cal /20.9
” then release both fingers.
5.
Press the "
Enter
Button", the Display value will count from 30 to 0, then return to normal measuring
screen and finish the calibration procedures. The complete calibration procedures will take 30 seconds
Calibration Consideration
a.
As the oxygen in air is 20.9 % typically, use the environment air 02 value for quick & precise calibration
b.
Please process calibration procedures under wide and ventilating environment for best effect.
9-3. Probe maintenance
Intend to let the DO probe keep the best condition, when user receive the Oxygen Probe, it should fill the
Probe's Electrolyte at first.
User already use the probe for a certain period:
Whenever user can
’t calibrate the meter properly or the meter's reading value is not stable, please check
the oxygen probe to see if the electrolyte in the probe head container is run out or the diaphragm (probe
head with diaphragm set) exist problem (dirty). If yes, please fill the electrolyte or change the "Probe
head with diaphragm set " and make the new calibration.
Calibration at first !
If it is the first time to use the Dissolved Oxygen meter or after a certain period
to use the meter again, then it should to execute the calibration procedures at
the first. For the measurement precisely consideration, it recommend to make
the calibration before each measurement
. Calibration procedure, see 8-2
