Sensorex CX105, Руководство пользователя

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6 Calibration
CAUTION:
All calibration procedures must be performed by trained personnel. Incorrectly set parameters may go
unnoticed, but will still change the measurement properties.
6.1 Wet Calibration (1 Point Sample
Method)
The “wet” calibration method requires the user to immerse the electrode into a properly
prepared conductivity reference solution of known value, or to keep the electrode installed in the
process while obtaining a process sample. When keeping the electrode installed, determine the
process value through a laboratory analysis of comparable reading. In either case, enter the
correct reference solution or sample conductivity value. The procedure is as follows:

Step 1 : Make sure the electrode is clean, and then immerse the electrode into solution. Stir
electrode in solution to ensure no bubbles.

Step 2 : Wait for the temperature to stabilize. Depending on how great the temperature
difference is, this may take up to 30 seconds .

Step 3 : Set the temperature to the value reading from a precision thermometer.

Step 4: Set the conductivity to a value, which is either from a solution or read from a precise
instrument.

Step 5: Place the electrode into a second different value solution, and verify the linearity. If
the transmitter does not display the correct value (temperature ± 0.5
℃
, conductivity ±2% of
reading), contact Sensorex technical support.
6.2 Dry Calibration (Simulates the Conductivity and
Temperature)
The Dry Calibration method requires the user to simulate the conductivity and temperature by
using precise fixed resistors (± 0.1%). The calibration procedure is as follows.
6.2.1 Temperature Simulation
The temperature input to the CX105 is a PT-1000 RTD, where 1000 Ohms ( Ω ) is equal to 0
℃
and a change of 3.85 Ω equals to 1
℃
difference. (1000 Ω = 0
℃
, 1096 Ω = 25
℃
)

Step 1: Connect a resistor (1000 Ω to 1096 Ω ) between the "Temp" and “Ground" terminals.

Step 2: Set the temperature in the same manner as the wet calibration procedure.

Step 3: Connect a different value resistor to the "Temp" and “Ground" terminals, and verify