Rosemount 2240S, Справочное руководство

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Reference Manual
300550EN, Rev AA
December 2010
Rosemount 2240S
5-6
Section 5. Configuration/Operation
5.3.2 Water Level
Sensor
Calibration
The Water Level Sensor (WLS) measures the free water level below an oil
surface. The WLS can be combined with Multiple Spot Temperature sensors.
The WLS is calibrated under the assumption that the dielectric constant
ε
r
=2.3 (diesel). The factory calibration values are stored in a separate write
protected Holding Register area.
The following parameters are stored in the factory calibration:
• Full = The measured capacitor value when the probe is completely
covered with water
• Empty = The measured capacitor value when the probe is completely
covered by the reference product
In case the dielectric constant of the product differs from factory calibration
you will need to perform a new
Empty calibration.
To calibrate the Water Level Sensor:
1. Lift the Water Level Sensor from the bottom of the tank and make sure
the sensor is covered by the product only.
2. Wait five minutes.
3. Press the ZERO button on the Rosemount 2240S for three seconds to
begin calibration (see Figure 5-3).
4. Wait for the Status LED to turn from a steady light to normal LED status
(2 sec. interval). Calibration error is indicated by blinking at a high
frequency.
5. When the calibration process is completed, anchor the Water Level
Sensor to the bottom of the tank.
Figure 5-3. ZERO button
ZERO button
LED signal