Analysis of the Advantages and Disadvantages of Double Rods and Single Rod Vibrating Rod Level Switch

Both double rods and single rod Vibrating Rod Level Switches are rod-shaped in appearance, but their internal structures are completely different.

Tube-11 Vibrating Rod Level Switch is a double-rods structure. Tube-11 Vibrating Rod Level Switch has been specifically designed for high level or low level point level detection of solids with a density of 0.02 kg/cm³ or greater. The vibration rod level switch operates and drives by piezoelectric ceramics. When the medium reaches the rod, the amplitude or frequency of the vibration probe substantially decreases, so does the output of detecting piezoelectric device. The amount of decrease is analyzed by an intelligent circuit which outputs a switching signal as a result. For Tube-11, the inner vibrating rod nests with the outer vibrating rod. When resonant frequency of inner and outer vibrating tubes is finely adjusted to the same value, both reliability and sensitivity of the vibrating rod level switch are extremely high.

For single rod structure probe, vibration energy transfers to the tank wall during operation. Due to the continuous loss of vibration energy caused by energy transfer to the tank wall, in order to maintain a reasonable and constant amplitude of vibration and continue working normally, it is necessary to appropriately increase the rod’s driving energy and continuously supplement the lost energy, which inevitably requires an increase in the driving voltage of piezoelectric ceramics, and this greatly shorten the lifespan of piezoelectric ceramics. In addition, increasing the driving voltage significantly reduces the detection sensitivity of the rod, making it unable to be applied to interface measurement.

For double-rod vibrating level switches, the resonance frequency of the inner and outer rods is completely consistent. The double rods vibrate simultaneously like symmetrical tuning forks, so that the vibration energy will not be transferred to the tank wall. Besides, only low voltage excitation is needed to drive the piezoelectric ceramics. The low voltage driving not only greatly improves the service life of the piezoelectric ceramics, but also significantly improves the detection sensitivity of the vibration rods.

Tube-11 Vibrating Rod Level Switch is a highly reliable level switch for point level detection of bulk solids with density greater than 0.02 kg/cm³. Tube-11 is often used with great success for high level sensing, low level switching and general point level indication for almost any material in your silo, bin or hopper, as well as stable and reliable performance in interface measurements. The double-rods design allows the level sensor to resist build-up and prevent silo overfill or product from running out with accurate level switching and no false signals.