September
2017
Sentinel V SC and RT Operation Manual
Page 126
EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page.
Figure 64.
Pressure Sensor Cavity with Sand
Use extreme caution to not touch or put any pressure on the face of the pressure sensor. The
sensor face contains a sensitive membrane that can be easily damaged. If the membrane is
damaged the pressure sensor will fail.
The pressure sensor is filled with silicone oil. Never poke a needle or other object through the
holes while the plate is installed over the pressure sensor. You could perforate the sensor,
causing it to fail.
Do not attempt to clean the surface of the pressure sensor. The diaphragm is very thin and easy
to damage.
Only use low-flow fresh water to flush out any sand in the sensor cavity.
If the pressure sensor surface looks corroded or is bowed outward, then contact TRDI for
servicing. Do not attempt to remove the pressure sensor. It is not replaceable in the field.
3. Attach the 10-gauge needle to the syringe. Draw approximately 2.5 cc of oil into the syringe. As
the plunger is drawn back, oil will slowly fill the syringe.
4. Fill the pressure port cavity with oil from the top of pressure sensor to the bottom of the copper
cover.
Have an absorbent paper towel on hand to clean up any overflow that may occur.
5. Gently clean out the holes in the pressure sensor cover with a needle. If the holes become enlarged
or the cover is corroded, replace the cover. The cover part number is 81D-4000-00.
6. Install the copper cover slowly, allowing time for the oil to pass through the holes. Tighten the
screws “finger tight”0.2 Nm (1.8 Pound-Force Inch). Do not over tighten as the threads on the
plastic screws may strip. If this happens, replace the screw (spare flat-head black nylon M3 screws
are included in the spare parts kit).
