Using Centroid 3-wire capacitive senders with CruzPro FU30/FU60 and TL30/TL60 electronic tankage gauges, set-up procedures and FAQS

Determine whether the sender uses the American or European type resistance curve:

American: Sender Resistance low when tank is full and high resistance when tank is empty

To setup a Centroid capacitive sender with European resistance curve for use with electronic gauges:
1) Connect the FU30/FU60 or TL30/TL60 gauge to the sender as normal and apply power to the instrument.
2) Connect the red lead of a voltmeter to the "Send" terminal of the Centroid capacitive sender.
3) Connect the black lead of the voltmeter to the "Negative" terminal of the sender.
4) Adjust both the "Empty" and "Full" adjustments on the sender to the fully CW position. Don't force the delicate potentiometers.
5) With an empty tank (or the sender suspended in air) - turn the "Empty" adjustment slowly CCW until the voltmeter reading stops dropping. Now turn the "Empty" adjustment back CW slightly until the voltmeter reads about 0.1V higher. For example, if the minimum voltage was 0.58 VDC, adjust for 0.68 Volts. The exact number is not important - the intent is to be somewhat above the minimum.
6) With a full tank (or outside the tank in a PVC tube full of the liquid to be measured) adjust the "Full" adjustment slowly CCW until the voltage drops about 0.1V. For example, if the reading was 2.23 V adjust the "Full" adjustment for approximately 2.13 V. Again, the exact number is not important, just be a little below the maximum.
7) Now you should have a smooth variation of the sender output from Empty to Full and the normal calibration procedure of the F60, FU60, TL55 or TL60 can be used following the procedures in the respective user's manuals.

To setup a Centroid THREE terminal capacitive sender with American resistance curve for use with electronic gauges:

1) Connect the FU30/FU60 or TL30/TL60 gauge to the sender as normal and apply power to the instrument.
2) Connect the red lead of a voltmeter to the "Send" terminal of the Centroid capacitive sender.
3) Connect the black lead of the voltmeter to the "Negative" terminal of the sender.
4) Adjust both the "Empty" and "Full" adjustments on the sender to the fully CW position. Don't force the delicate potentiometers.
5) With an empty tank (or the sender suspended in air) - turn the "Empty" adjustment slowly CCW until the voltmeter reading stops increasing. Now turn the "Empty" adjustment back CW slightly until the voltmeter reads about 0.1V lower. For example, if the maximum voltage was 2.58 VDC, adjust for 2.48 Volts. The exact number is not important - the intent is to be somewhat above the minimum.
6) With a full tank (or outside the tank in a PVC tube full of the liquid to be measured) adjust the "Full" adjustment slowly CCW until the voltage increases about 0.1V. For example, if the reading was 0.58 V adjust the "Full" adjustment for approximately 0.68 V. Again, the exact number is not important, just be a little below the maximum.
7) Now you should have a smooth variation of the sender output from Empty to Full and the normal calibration procedure of the F60, FU60, TL55 or TL60 can be used following the procedures in the respective user's manuals.