31
ENGLISH
Autodos M
MA60-10E
ENGLISH
Autodos M
MA60-10E
Some buffer solutions for redox and approximate readings:
Mixture
Redox potential
at 20°C
at 25°C
at 30°C
Buffer pH 2 + quinhydrone
385 mV
381 mV
377 mV
Buffer pH 4 + quinhydrone
268 mV
263 mV
258 mV
Buffer pH 7 + quinhydrone
92 mV
86 mV
79 mV
Buffer pH 8 + quinhydrone
33 mV
27 mV
19 mV
Mix one dose of quinhydrone powder in 20 ml buffer fluid. Stir it weill untill the solution is saturated.
Note: Quinhydrone solution is unstable and must be discarded after use. The time required for stabilization of the new measure-
ment value is an indication of electrode condition as age and contamination increase stabilization time.
Calibration Chlorine
Calibration of chlorine electrodes shall be done with a measured value of the water in direct connection to Autodos and with a
digital photometric instrument. If the pool water is dosed or has been dosed with organic chlorine containing isocyanuric acid,
the pool water shall be controlled. The level of cyanuric acid can not exceed 5mg/l (ppm). An increased level will give lowered
free chlorine signals which affects calibration, measuring and control of relevant cannel.
Chlorine electrodes are flow dependent and the flow through the valve shall be adjusted to 30-40 liters/minute.
Zero point calibration
Zero point calibration should be done, see 2 under Calibration/Chlorine. An inaccurate zero point will give errors in calibrations
and display of chlorine values.
Lift the electrode (with the electrode cabel connected) from the valve, wait for one minute.
If the chlorine display shows other than 0,00: Activate calibration mode by pressing and holding the
Cal.
button [0] until the “
Ac-
tive
” LED illuminates.
Press the button ↓ for 4 seconds until the display shows: -, -, -, - - -, after that the calibration is done. To reset the zero point
calibration to factory mode, press the button ↑ for 4 seconds until the display shows: F, F, F, FFF, after that the reset is done.
NOTE! If the signal at zero point calibration deviates too much from the expected value, electrode error will be indicated with the
text ”
EL1
”, ”
EL2
” during the time the calibration button is pushed.
When the button is released, Autodos M uses the calibration values that applied before the failed calibration attempt.
Meaning of the texts:
EL1
active electrode error 1 (low calibration point < min)
EL2
active electrode error 2 (low calibration point > max)
Calibration – free chlorine: PB-200 chlorine electrode
(Gain calibration)
The reinforcement mode is limited both upwards and downwards by levels of reasonable electrode signal.
1. Activate calibration mode by pressing and holding the
Cal.
button [0] until the “
Active
” LED illuminates.
2.
Zero point calibration is carried out by lifting the electrode out of the flow cell, waiting about 1 minute and then pressing the ↓
button under display 1. Before calibration to the laboratory-measured value is possible, the electrode must be 3. refitted in the
flow cell and allowed to measure in the cell for about 2 minutes to obtain a correct value.
3. Access calibration mode by pressing and holding the
Cal.
button [0] until the “Adjust” LED illuminates. The meter stores the
last measured electrode signal.
4. Take a water sample and determine the correct chlorine value with DPD1.
5.
Set the correct chlorine value with the ↑ and ↓ buttons under display 1..
6. Exit calibration mode by pressing and holding the
Cal.
button [0] until the “
Adjust
” and “
Active
” LEDs go out.
