wtw pH 1970i, Руководство по эксплуатации

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Operation pH 1970i
26 ba75690e01 01/2007
Three-point calibration
Note
You can prematurely terminate the three-point calibration by pressing
<M> . The values of the two-point calibration for slope and asymmetry
will then remain stored.
4.3.2 AutoCal DIN
For this procedure, use two or three different standard buffer solutions
according to DIN 19266 in ascending or descending order (type A, C,
D or F with pH values at 25 °C of: 1.679 / 4.006 / 6.865 / 9.180).
Note
The buffer solutions are automatically recognized by the measuring in-
strument. Depending on the instrument setting (see
section 4.6 C
ONFIGURATION
), the instrument displays the relevant buff-
er nominal value or the current electrode voltage in mV.
Note
Skip the steps 2, 7 and 14 if you use a temperature sensor.
12 Press the <RUN/ENTER> key
to continue the three-point calibration .
Ct3 appears on the display.
13 Thoroughly rinse the electrode with distilled water.
14 If necessary, enter the temperature of the third buffer solution
with
<
▲
> <
▼
> .
15 Immerse the pH electrode in the third buffer solution.
16 Press the <RUN/ENTER> key.
The AR display indicator flashes.
The electrode voltage (mV) or the buffer nominal value ap-
pears on the display.
When the measured value is stable,
AR disappears.
The instrument displays the value of the slope (mV/pH) and the
evaluation of the calibration in calibration range II.
17 Press the <RUN/ENTER> key.
The instrument displays the value of the asymmetry in calibra-
tion range II. The three-point calibration is completed.
18 To return to the measuring mode: Press the <M> key.