Emerson Rosemount 2240S, Reference Manual, Page: 63 / 194

53
Reference Manual
00809-0100-2240, Rev DA
Configuration/Operation
October 2017
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 factory calibrated for a 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 capacitance value when the probe is completely covered with water

Empty = The measured capacitance 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. In this case empty means that there is no water, i.e. the sensor is fully immersed
in oil.
Calibration procedure
1. Lift the Water Level Sensor from the bottom of the tank and ensure the sensor is covered by the
product (oil) only.
2. Wait five minutes.
3. Press the WLS Calibration button (A) on the Rosemount 2240S transmitter for at least two seconds
to start calibration (see Figure 5-3 ). Calibration is indicated with a steady LED light for about 10
seconds, then it is turned off.
4. When calibration is finished the status LED lights up with a steady light for about ten seconds. In case
of a calibration error, the LED blinks at a high frequency for 10 seconds, see Figure 5-4 .
5. Wait for the Status LED (B) to turn from a steady light to normal LED status (blinking with 2 seconds
interval).
6. Once the calibration process is completed, anchor the Water Level Sensor to the bottom of the tank.
Figure 5-3. ZERO button and LED status signal
A. WLS Calibration
B. LED status signal
A B