TECH-AIRE INSTRUMENTS, INC.
Tech-Aire Instruments, Inc. was established in 1982 with the initial goal to provide a source for reliable and reasonably priced sales and service for your instrument requirements. Tech-Aire Instruments, Inc. has evolved into a customer-oriented business, wher we have a large instrument exchange pool, knowledgeable sales staff, experienced technicians, a good quality system, and excellent turn times.
TROUBLESHOOTING THE CESSNA CAPACITANCE FUEL QUANTITY INDICATING SYSTEM
The quantity gauge can be very useful in determining and isolating problems. Certain problems produce definite indications. For instance:
A short between Hi-Z and Lo-Z will cause the gauge needle to register off scale "low" regardless of fuel level in the tanks or signal conditioner adjustments.
A short between Lo-Z and ground or Lo-Z and shield will cause the gauge needle to register a constant zero regardless of fuel level or adjustments.
Moisture in the probes or more importantly inside a connector plug will cause the gauge needle to register off scale "high" regardless of fuel level or signal conditioner adjustments. This same condition will occur if Lo-Z is shorted to Lo-Z 2.
An open Hi-Z or Lo-Z will cause the gauge to read less than actual fuel quantity, but the gauge will respond to changes in fuel quantity and signal conditioner adjustments.
Grounding of Hi-Z will cause an approximate 1/3 to 1/2 gauge indication, again, unaffected by changes in fuel level or signal conditioner adjustments.
Poor shielding, loose terminals, corroded connectors or intermittent shorts will cause the gauge needle to fluctuate.
To isolate the problem, start at a point as far from the signal conditioner as possible and work inboard toward the signal conditioner. Disconnect the probes one at a time noting whether or not a change occurs on the gauge... if it does, you have found the defective part of the system.
Recommend Product
