5 ph calibration, Ph calibration – Xylem PH3210 FIELD PH METER User Manual
Page 34
Operation
pH 3210
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4.4.5
pH calibration
Why calibrate?
pH combination electrodes age. This changes the zero point
(asymmetry) and slope of the pH combination electrode. As a result, an
inexact measured value is displayed. Calibration determines and
stores the current values of the zero point and slope of the electrode.
Thus, you should calibrate at regular intervals.
When do you have to
calibrate?
z After connecting another combination electrode
z When the calibration interval has expired
Buffer sets for
calibration
You can use the buffer sets quoted in the table for an automatic
calibration. The pH values are valid for the specified temperature
values. The temperature dependence of the pH values is taken into
consideration during the calibration.
No.
Buffer set*
pH
values
at
1
ConCal
Any
Any
2
NIST/DIN
DIN buffers according to DIN 19266
and NIST Traceable Buffers
1.679
4.006
6.865
9.180
12.454
25 °C
3
TEC
WTW Technical buffers
2.000
4.010
7.000
10.011
25 °C
4
Merck 1*
4.000
7.000
9.000
20°C
5
Merck 2 *
1.000
6.000
8.000
13.000
20°C
6
Merck 3 *
4.660
6.880
9.220
20°C