New Autoresonant Vibrating Wire Piezometer

The Model 4500AR piezometer is designed to be used with readout systems that can read frequency but do not have the capability to “pluck” the VW gage. This sensor has built-in electronics that cause the gage wire to vibrate in a continuous mode at its resonant frequency. The output from the sensor is a 5 volt DC square wave at this frequency. A DC input voltage in the range of 6- 24 volts is required to operate the gage. The current consumption is approximately 21 mA at 12 VDC. The gage output is independent of the input voltage.

Multiple sensors powered simultaneously can be read, up to 5 sensors per second, and dynamic measurements on a single sensor can be made up to 20 Hz. Upon power up, the gage will immediately start to “ring” at the resonant frequency and will continue to do so until the power is removed. Continuous operation will have no effect on the gage life.

Note: The sensor comprises two transducers, the VW pressure sensor and a thermistor for measuring temperature. The signals from the VW transducer are high level frequency and will interfere with the thermistor output if left powered during the period that the thermistor is being read. If the temperature reading is important the power to the pressure sensor should be switched off while the reading is taken.