Endress+Hauser Liquisys M CUM223, Руководство по эксплуатации

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Commissioning Liquisys M CUM223/253
64 Hauser
6.6 Calibration
Measuring chain calibration is performed in this function group.
The calibration data are saved in an EEPROM directly in the sensor. For this reason:
• Recalibration is not required in the event of a power failure
• Recalibration is not required when the transmitter is replaced
• Customer-specific recalibration is required, however, when the sensor is replaced
Three calibration data records are saved in the sensor for each of the four main operating
modes.
Select the desired data record in the SETUP 2 function group in the B4 field.
• In the FNU operating mode, the sensor is factory calibrated with formazine traceable to
ISO 7027.
• In the ppm operating mode, the calibration data records for Kaolin and SiO
2
are derived
from the FNU data records.
• In the % operating mode, the calibration data records are set to the average of various
residual concrete waters. They are preset in such a way that correct values are displayed
for average clarity. However the settings do not follow a standard currently applicable.
• In the g/l operating mode also, the sensor is not calibrated to a fixed value as no standard
is directly applicable. You must carry out a calibration because the media of the various
applications differ too greatly here.
Three-point sensor calibration is the standard calibration. It is absolutely essential :
• When commissioning the sensor in sludge applications
• When changing to another sludge type
Three-point sensor calibration is
not necessary:
• When commissioning the sensor in the drinking water area (sensor has been calibrated
for drinking water applications in the factory).
• For residual concrete water. Density measurement for determining the concentration of
residual concrete water is based on %–data records. They are preset in such a way that
correct values are displayed for average clarity. One-point calibration is often sufficient to
adjust the system in the event of deviating values.
• When recalibrating with the same sludge type. One-point calibration suffices here if the
degrees of lightness and clarity, for example, do not differ too greatly.
FNU/NTU ppm or mg/l g/l %
Factory data record no. 1
not changeable
Formazine SiO
2
Activated sludge Residual concrete
water
User data record no. 2
changeable Formazine Kaolin Activated sludge Residual concrete
water
User data record no. 3
changeable
Formazine SiO
2
Activated sludge Residual concrete
water