EUTECH INSTRUMENTS Alpha CON 500, Инструкция по эксплуатации, Страница: 15 / 36

Instruction Manual CON 500
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5 C A L I B R AT I O N
5.1 Important Information on Transmitter Calibration
Calibration should be carried when you are using your transmitter with a new
electrode for the first time or when you suspect that the transmitter/electrode is out
of calibration. Your transmitter allows you to perform temperature calibration and
conductivity calibration.
As temperature readings affect the accuracy of conductivity measurements, it is
recommended that temperature calibration should be carried out only if the
temperature value displayed on the transmitter is different from that of a calibrated
thermometer. A temperature offset calibration of ± 5 °C from the default reading is
allowed. Once a temperature calibration is performed, conductivity calibration
should be carried out to ensure the accuracy of conductivity measurements are
maintained.
Your transmitter has up to six selectable conductivity measuring ranges. The
selection for the sixth range, range 6 (0.00 to 199.9 mS/cm), only appears in the
Setup mode if the cell constant is selected to be K =1.0 or K =10 whereas range
1(0.00 to 19.99uS/cm), will only appear when cell constant is selected to be K = 0.1
or K = 1.0. Other wise, the selection will be limited to five ranges only.
You can only calibrate one point in the measuring range that you have selected for
your process application. You have to recalibrate your transmitter every time you
change the measuring range since the calibration data of your transmitter will be
erased every time a new measuring range is selected.
During conductivity calibration, the transmitter allows a calibration window of ± 40%
from the measured default reading of the calibration standard. The minimum
allowable calibration point is 10% of the full scale reading of the range selected.
For best results, select a standard value close to the sample value you are
measuring. Alternatively use a calibration solution value that is approximately 2/3
the full-scale value of the measurement range you plan to use. The following table 1
lists the corresponding conductivity ranges. You should calibrate, in the range that
you have selected, using a solution that falls between the values in the
“recommended calibration solution range” column.