Vibronic level switch
Piezoelectric effect
Function description The Liquiphant vibration probe analyses the change in frequency which is produced by a liquid on the sensor. The symmetrical fork paddles start vibrating piezoelectrically at their resonance frequency. The application of a voltage makes the piezo expand and the metal membrane is bent due to the rigidity of the ceramic disc. The main characteristic of the bimorph drive is its mechanical insensitivity. |
Bimorph drive |
Evaluation electronics Detection of frequency shift |
Transmitter |
Common electrode |
Receiver |
Resonant circuit |
Force |
Force |
Ceramic disc |
Piezoelectric effect |
Vibronic level switch
Application limits and utitlization conditions |
Viscosity change |
Outside vibrations |
Suspension |
Density change |
Electric property |
Liquiphant vibration limit switch |
Medium temperature: |
Operating pressure: |
Solids proportions: |
Density: |
Viscosity: |
-58 to +300F (-50 to +150°C) |
-15 to +900 psi (-1 to +63 bar) |
min. 0.5 g/cm3 |
1 mm2/s up to 10,000 mm2/s |
max. diameter of 0.2" (5mm) |
Scale formation |
Foam |
Pressure and temperature change |
Turbulences |
Air bubbles |
Changing media |
For more information: Endress+Hauser GmbH