Polymetron SODIMAT 9073, Instruction Manual

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SODIMAT - Model 9073
6-4
Warning : do not forget to put back the filter after the calibration is
completed.
Note 1 :
- Pressing SELECT interrups the calibration
- Pressing ENTER validates the measurement before the required time (if the measurement
is considered stable).
Note 2 :
- C251 and C261 permit to control the new offset and slope values.
- It is possible to take a note of these values in Appendix B to check the electrode
evolution.
The analyser is then able to calculate the new offset and slope.
If any big difference after the calculation compared to the theoric values, the following error
message is displayed.
6.3.2 AUTOCAL calibration
The sodium concentration of the calibration solution to be prepared depends of the sodium
contained in the water to analyse. The values advised below will ensure a utmost accuracy :
Water to analyse Calibration Addition 1 generated Addition 2 generated
(ppb Na*) solution (ppb) flow rate = 4 l/h (ppb) flow rate = 4 l/h
< 0.5 ppb 10 ppm 954 87.1
< 1.9 ppb 1 ppm 95.4 8.71
< 3.8 ppb 2 ppm 190.8 17.42
< 9 ppb 5 ppm 477 43.56
< 38 ppb 20 ppm 1908 174.2
< 90 ppb 50 ppm 4770 435.6
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Preparation of a 2 ppm Na calibration solution :
ì
Prepare a stock solution 1 g/l Na (1000 ppm) :
Weigh 2.541 g of NaCl dry and dissolve it in one litre demineralised water, free of sodium.
This solution should be kept in a cool and dry place, its lifetime is 6 months.
í
From the stock solution :
Take 2 ml of the stock solution and dilute it in one litre demineralised water to obtain a 2
ppm Na calibration solution.