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7.4.2 – END OF OIL Sensor Adjustment
The end of oil sensor detects the meniscus created in the capillary tube when the sample vial has emptied
and freezes the DL and DS readings completing the sample test. Occasionally, you may encounter oils
that contain large particles that are big enough to prematurely trigger the end of oil sensor. To prevent
this, the sensor’s sensitivity can be adjusted. This is done by testing oil suspected of containing large
particles using the DR-7’s end of oil calibration feature in the CALIBRATION tab. This procedure is
useful when conducting a large batch of samples with large particle properties. For single samples the
alternate method is suggested to bypass the End of Oil sensor.
To adjust the end of oil sensor:
1.
Select the CALIBRATION tab.
2.
Press the END OF OIL button to calibrate the end of oil sensor.
3.
Press START and run the sample as usual.
4.
Throughout the test the end of oil sensor’s min and max values will be displayed.
5.
When the sample vial has emptied, press EXIT/ STOP
before
the oil meniscus goes past the end of
oil sensor in the precipitator capillary tube.
6.
The program will then take the absolute value of the larger number, min or max and set the new
threshold by adding 10 to the number. For example, if the largest number was 20, which represents
the largest particle seen by the sensor, the program then adds 10 to the number and sets the new
threshold value. The end of oil threshold is set at the factory to 10. This is usually sufficient for most
oils, and you may never have to change this value.
7.
To set the end of oil sensor back to the default setting press the default button and the threshold
number will be set back to 10.
