E1001A-171107
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5.3 SATURATING THE TUBING PROBE ASSEMBLY
1. Connect the extremity of the Tecalan tubing fitted with the quick connect to port No. 1.
Thread the other end of the tubing through the probe to rod adaptor and connect it to
the probe. Tighten the nut using two wrenches. Do not over tighten: the brass nut is
fragile and may crack. Lay down the probe next to the control box.
2. Remove the plug located at the lower extremity of the probe. Hold the probe bottom
end up slightly inclined and with the saturation outlet in the 12 o'clock position.
3. With the valve No. 6 on "TEST", inject water into the probe by rotating the crank handle
clockwise until bubble free water only is flowing out of the saturation outlet of the probe.
Stop turning the crank handle. Put the plug in place and tighten.
4. Put the probe in the calibration tube. Inject fluid in the probe and pressurize it up to
8,000 kPa. Hold pressure for three minutes and check for leaks around the probe. Start
deflating the probe. Remove the probe from calibration pipe as soon as possible. Keep
on deflating the probe until it looks deflated (uniform diameter). Do not deflate it too fast
– see warning in following section. Do not deflate it too much, otherwise gaps between
the metal fins on the probe will open. These must remain closed as much as possible.
5. Disconnect the Tecalan tubing from port No. 1. Refill the cylinder by placing valve No. 6
on "FILL" and returning the piston to its lowermost position. Wait a few seconds.
6. Repeat step 4.2 as a final check on the saturation of the unit.
7. Disconnect the tubing from port No. 4.
8. The instrument is ready to be calibrated. The instrument, probe and tubing can be
saturated in advance and transported to the site ready for testing.
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CALIBRATION
6.1 CALIBRATION FOR PRESSURE CORRECTION
This calibration must be done each time a new sheath is put on the probe. It allows to
measure sheath resistance. Typically it ranges from 30 to 100 kPa at 1600 cc for an N-
size probe.
1. The probe is placed at ground level and is unconfined.
2. Connect the Tecalan tubing to port No. 1.
3. Place valve No. 6 on "TEST".
4. Rotate the small crank handle clockwise at a rate of 1 revolution every 2 seconds, until
80 cc have been injected (long 70 mm probe) or 40 cc (44 mm probe).
5. Stop the injection, wait 30 seconds and record the pressure and the volume.
6. Continue this procedure until 1440 cc are injected for 70 mm probe or 760 cc for 44 mm
probe.
7. Slowly rotate the crank handle counter clockwise to return the piston to its initial position.
8. Check the curve of injected volume versus pressure.
Warning: Deflation of the probe must always be done slowly (less than 1 revolution
every 2 seconds) to prevent air infiltration in the pressuremeter. Negative pressure
should not go under - 50 kPa. Once in a while, stop cranking and wait for the
pressure to come back close to 0 kPa before resuming cranking.