G) Ph Calibration - VOLTCRAFT PHT-200 Bedienungsanleitung

pH 10 reference value
The first decimal point starts flashing in the bottom line. Here, the reference value for the pH 10 calibration is set. Read
the appropriate value on the packaging of the pH10 buffer solution at the temperature determined. The adjustment
range is from 9.80 to 10.20 pH.
After entering the value, press the "TEMP.C" key. The setting process is ended and switched to the measuring mode.
If a pH value is not exact for your temperature, take the value closest to your temperature.
If a reference value is not required, this setting step can be skipped using the "TEMP.C" key.
The set reference values are adopted during the pH calibration if the corresponding buffer solution (pH 4.00 /
pH 7.00 / pH 10.00) is not available.
Automatic temperature compensation.
• For automatic temperature compensation, connect the optional temperature sensor to the measuring device
("TEMP PROBE INPUT" socket (10)).
• Switch the measuring instrument on. As measuring function, "PH" must be shown on the display. If this is not the
case, switch over the measuring function with the "PH/mV" key.
• Place the probe tip in the liquid to be measured. The temperature is now automatically recorded and displayed in
the lower display line.

g) pH calibration

A pH calibration (adjustment) is required when the measuring device is used for the first time or after storage. For
accurate measurements, it is recommended to perform the calibration before each measurement. In order to achieve
the highest possible accuracy, it is advisable to always carry out a 2-point calibration.
The neutral calibration with pH 7 is always required (1-point calibration).
The second calibration point for acidic liquids (<ph 7) must be a pH 4 buffer solution. For alkaline liquids (> pH 7), a
buffer solution with pH 10 must be used. The calibration points pH 4 and pH 10 cannot be calibrated at the same time.
Choose the appropriate area depending on the application.
Calibration requires buffer solutions. The scope of supply includes a pH 7 buffer solution for neutral calibra-
tion and a pH4 buffer solution for acid calibration. Alkaline buffer solutions for pH 10 are optionally available.
Always perform temperature compensation before calibration. For automatic temperature compensation,
insert the optional temperature probe with the pH electrode into the buffer solution at the same time.
If problems occur during calibration, the default factory settings can be restored. Please proceed as follows.
• Press the "CAL." key (6). While the display is flashing, press the "PH/mV" key (8). The original default value will
be restored.
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