PiezoVelocity Transducers (PVT®) are solid state piezoelectric velocity measurement devices. Since many vibration analysts prefer to examine vibration signals in terms of velocity (inches per second or ips) to amplify the signal of interest. PVT’s inherently decrease high frequency signals allowing better measurement of low frequency vibration.
PVT sensors are essentially accelerometers with an internal integration circuit which will produce an output relative to velocity.
System Noise Advantages
PVT®’s can reduce signal noise in many low frequency measurements. The integration circuit amplifies low frequency signals and attenuates high frequency signals. This increases the voltage output at low frequency and filters high frequency noise. The increase in low frequency voltage output reduces the noise contribution of the acquisition equipment. The inherent filtering reduces intermodulation (washover) distortion caused when high frequency signals overload the amplifier and may reduce “ski slope” noise in many applications.
Steam seals in paper machine dryers can leak and produce very high frequency noise. This high frequency noise can overload normal accelerometers and “washover” low frequency information. The PVT® attenuation of high frequency signals ensures that quality data can still be taken in areas prone to steam leaks.
Pumps and piping are susceptible to cavitation problems. The collapse of the cavitation pockets produces very high frequency noise that can also overload an accelerometer. PVT’s allow effective measurement of normal vibration in the presence of severe cavitation.
|Model||Sensitivity||Sensitivity tolerance +/-||Frequency response @ +/- 3db||Max temp.||Accel Range||Haz area option|
|793V||100 mV/in/sec||10%||1.5 - 7k||120°||50 in/sec||Y|
|797V||100 mV/in/sec||10%||1.6 - 7k||120°||50 in/sec||Y|