English to Russian Science Chemistry; Chem Sci/Eng

Calibration
Calibration of pH probe:
The calibration of the pH probe uses a two-point calibration method (zero point, slope). As buffer pH 7 (zero point calibration) and pH 4 (slope calibration) are factory-set. If other buffers are to be used, the defaults in the complete operating menu (menu A, B) may be altered. During calibration control is stopped and metering is reduced to the set base load. The output 0/4...20 mA (measuring value) will be frozen. After successful calibration, all fault determinations relating to the measuring value are started again. The current probe data (zero point/slope) will be displayed.

Calibration of the chlorine probe
The calibration (slope calibration) of the chlorine probe uses the DPD method. When starting calibration, the frozen measuring value is proposed; this value may be adjusted to the measured DPD value using the Up and Down buttons. A calibration will only be possible if the DPD value is і 2% of the measuring range. During calibration, control function and metering are maintained. After successful calibration, all fault determinations relating to the measuring value are started again.

With a measuring range adjusted to 0 - 0.5 ppm, the zero point may be calibrated in the entire operating menu in addition to the slope. The zero point calibration should be performed under realistic condition with chlorine-free water. In this case, control will be stopped and metering will be reduced to the set base load. The output 0/4...20 mA (measuring value) will be frozen.