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KPSI Level & Pressure Transducers: Application NotesTroubleshooting Submersible Pressure Transducers |
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Readings of 30 mA on a 4-20 mA output device indicates that the unit is no longer in calibration and needs to be returned to the factory. This condition is often caused by lightning strikes or other high-voltage transients that damage the instrumentation amplifier. Actual Level Exceeds Indicated Level Consistently lower readings can indicate a build-up of a liquid column in the cable vent tube. If you happen to get water in our vent tube and in the submersible pressure transducer, coil the cable and place the cable and transducer in a pan and place the pan in an oven at 50ºC for 2 hours. This on-site remedy may do the trick. Be careful that the oven temperature does not exceed 50ºC. Otherwise, you may damage the transducer and cable. Alternatively, you may suspend the cable and unit in a vertical position overnight to allow water to drain from the transducer and the cable vent tube. Reading is Within Range But "Freezes" at One Point Even though the input end of the level sensor is relatively self-cleaning, certain environments may induce the formation of "crust" over the sensor diaphragm preventing the sensor from identifying change in level. Removing the sensor from the media and cleaning it with a mild detergent will solve the problem. To combat marine growth, you might try wrapping our transducers with copper wire similar to that found in wire scouring pads for doing dishes. Marine growth occurs on the copper and eventually erodes the copper and drops off or the copper is manually removed during routine maintenance. Alternatively, there are various companies that will impregnate/coat the 316 stainless steel with antifouling chemicals or coatings. Similarly, level sensors temporarily removed from the well or sump should not be stored dry, but should be stored in a bucket of fresh water in order to prevent "crust" formation. Readings Increasing Very Slowly Over Time Our cable is shipped coiled and consequently takes time to straighten when installed. Attaching a weight to the transducer (i.e., one of our sacrificial anodes) will help. In order to prevent cable stretch with lengths greater than 200 feet, secure the Kevlar fibers (just under the black cable jacket) to the junction box or other immovable object. No Electrical Output From the Transducer Check all connections to ensure they are correct and secure. Double check your power supply or power the transducer from a battery (i.s., 9V lantern or 12V car). If everything checks out ok, the problem may be with our circuit board or sensor. The unit will need to be returned to the factory for evaluation. Most probable cause of this type of failure is damage to the submersible cable jacket allowing water to leak down the cable and into the transducer housing.  return to KPSI Level and Pressure Transducer Application Notes
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