Working Principle of Vibrating Fork Level Sensor

Working Principle of Vibrating Fork Level Sensor Vibration fork switches can be used where you will need point level measurements. Basically they designed with a tuning or oscillating fork that will resonate in the air having certain known natural frequency.

This resonance frequency will be reduced if the fork is brought in contact with the medium. The working principle of a​ vibrating fork level sensor​ switch is quite simple, yet effective. This principle is used to make level switches of vibrating fork type, something like tuning fork type of level switches.

They are much more cost effective, reliable, and quite popular for applications, where the detection of the liquid presence (or absence) is critical. They are quite effective even when bulk solid materials are used.

The working principle of vibrating fork level sensor switch is dependent upon detecting change in the sensing element’s harmonic vibration frequency, as a result of coming in contact with a target media.

Also, these level switches use sensing element, which is tuning fork shaped, having two tines inserted inside the tank or a bin, where the target media is present.

Tuning fork type sensing element will be placed into vibration or motion. That will become the natural resonating frequency of the sensing element, or the fork. The most basic working principle about vibrating fork type of level switch is the harmonic vibration of tuning fork sense element, which in turn creates Piezoelectricity.

There are typically 2 piezoelectric crystals or elements that are made of quartz. As these crystals will be compressed or pulled, they will generate certain electric signal. Also, conversely, the electricity will be applied to such crystals, which in turn produce motion.

Such motion will be attached to fork sense element and will vibrate at natural resonant frequency. Another piezoelectric crystal will be used for transforming motion received from first crystal back to electric signal.

As fork sensing element will vibrate free in air, measuring system will see this as a certain state.

When target material or the fluid becomes present, frequency of vibration will get changed and electric signal of second crystals changes, thereby detecting material or presence of fluid.

Advantages 1. This kind of sensor switch remains totally unaffected by bubbles, flow, foam, coating, vibration or the properties of the liquids.

2. There is a possibility of doing advance checks and also diagnostics to make sure about its reliability at both low- and high-level applications.

However, this type of sensor switch may not be too effective for viscous media as the materials between forks may disturb the measurements.

Sapcon​ manufactures the best vibrating fork level sensor in India. It is an Indian company but they manufacture precision products as per the international standards. The company is certified EL Class-I by EHEDG, and their products can withstand application temperature ranges up to 150° c.

You can visit their website to see the product range of vibrating fork level switches, which are suitable for all types of liquids with viscosity maximum up to 10,000 cp, and density that is greater than or almost equal to 0.7gm/cc.