8
7.1. CONNECTION SCHEME
Description of the connectors sectors:
-12V • power supply - Negative;
+12V • power supply - Positive;
• conductivity cell braid cable;
CS • conductivity cell central cable;
Pt1000 • two cables of the temperature probes (exchangeable);
pH • pH electrode central cable;
• pH electrode braid cable.
7.2. CALIBRATION OF THE PH ELECTRODE
INTRODUCTION
Before starting the measurement using a new electrode, this should be calibrated. The absence of calibration
would result in important measurement errors. The calibration is carried out with different standard solutions of:
pH 4.00,7.00 and 9.00. It is possible to calibrate from one to three solutions. The more calibration points are used,
the more accurate the measurement will be over the whole range. The selection of the order of using the standard
solutions is free. If you wish to use just one standard solution, its value should be as close as possible to the
estimated value of the measurement. In the case of the measurements that do not require high accuracy, it is enough
to perform the calibration of a point using the buffer solution pH 7.00.
The values of the buffer solutions are related to a temperature of 20 0C. If the temperature differs a lot, the buffer
solutions should be heated or cooled. Basically, the difference of ±5 0C, will not affect the result.
PH CALIBRATION
Press the key until in the lower left corner of the display shows the CAL symbol.
The calibration parameters will be deleted immediately.
Insert the electrode and the temperature sensor in the pH 7.0 solution, the tool will recognize the value of the pH
standard and the P1 symbol will appear (calibration point). The reading value may be different from the current value of
pH7.0. Insert the electrode and the temperature sensor in the pH4.0 solution, the instrument will recognize the value of
the pH automatically and the P2 symbol will appear. The value may be different from the current pH4.0 value.
When the value on the display will be stabilized press the key below the display on the left.
The value on the display will flash to show the correct memorization of the calibration value. At the same time, the
measured value will be aligned to the buffer value used.
The calibration can be terminated by pressing the button below the display on the left until the CAL symbol
disappears.
If the value of the used solution (buffer) is different from the memorized one and cannot be detected by the device or
if the connected electrode of the instrument is broken this symbol will appear
