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Running an Opaque Sample:
1.
Press the OPAQUE button.
2.
Enter the control number, if used, by pressing the ENTER CONTROL NUMBER button, as
explained in the Standard Operation section.
3.
Pump 4 ml of heptane into a clean sample vial to be placed in the vial holder on top of the DR-7 next
to the prepared oil sample.
4.
A base line must be created the first time an opaque sample is run. Place the small end of the
precipitator tube in the sample vial of heptane and press RUN BASELINE.
5.
When the DR-7 is calibrated on the heptane, the pump will reverse and shut off the flow of the
heptane. At this point change the precipitator tube to the sample vial with the oil sample, inserting the
tube all the way to the bottom of the sample vial. Press the START
button and this starts the flow
again.
6.
When the last of the oil sample is in the precipitator tube, quickly move the tube to the vial that
contains the heptane. This will wash the dark material out of the precipitator tube, and you will get
the actual DL and DS readings. By moving the precipitator tube in and out of the heptane, air bubbles
will be introduced into the capillary tube. These bubbles will help remove the opaque oil and
nonmagnetic material in the precipitator tube.
7.
When the heptane is gone and the flow has stopped in the capillary tube, take the DL and DS
readings. Press the COMPLETE button to save these readings.
8.
To start another opaque test. Place a newly prepared sample into the vial holder along with a sample
vial of heptane for washing. Replace the precipitator tube and place the capillary tube end into the
new sample and then push the START
button again to use existing baseline that was established with
the first opaque test. Run this test with the capillary end of the precipitator tube in the oil sample
transferring it to the heptane at the end of the test to flush the precipitator tube and obtain the DL and
DS readings.
9.
To end the OPAQUE operation press STOP to exit out.
