Capacitive Sensor For Water Level Measurement

Performing system calibration using labview software can help achieve higher accuracy.

Capacitive sensor for water level measurement.

Capacitive sensor for water level detection has been fabricated. Capacitive level transducer is an example of indirect measurement of level capacitance level sensors are used for wide variety of solids aqueous and organic liquids and slurries. In this research water level sensor based on capacitive principal created using two copper plates with height h width b and distance l between two plates respectively 0 040 m 0 015 m and 0 010 m. They measure the change in capacitance between two plates produced by changes in level.

Capacitance level sensors operate in the way that process fluids have dielectric constants significantly different to air. It has typically high impedance sensor particularly at low frequencies as clear from the impedance reactance expression for a. Capacitive liquid level sensors have been widely used for water fuel oil etc. There are two types of capacitive level sensor contact type or non contact type for water level measurement.

The measurement principle is not affected by the density variation of the media. Dielectric constant between two plates is proportional to water level. The technique is frequently referred as rf as radio frequency signals applied to the capacitance circuit. Capacitive water level sensor is manufactured on well developed capacitive technology and widely used for liquid level measurement.

Experimental results confirm that the sensor described in this paper has high linear sensitivity good repeatability low cost low energy and simple installation. Also capacitive sensor is a noncontacting device in the common usage. They are also widely used in water treatment applications for pump control and open channel flow measurement. Capacitive measurement has a very fast response time which makes it ideal for processes with fast level changes and small containers.

Applications tank level monitoring in chemical food water treatment power and brewery industries. The capacitive level measurement can be used in aggressive media when a fully coated probe e g. ε r eff 1 ε r 2 from this equation the measured capacitive is proportional to the length submerged into water as the approximate capacitance per length of track for a coplanar sensor remains constant. For d h 1.

An effective interdigital capacitive sensor for the water level measurement range of 0 30 cm with 0 2 cm resolution has been proposed designed and realized. 5 v pp 3 khz ac signal is used as input signal for the system. Ultrasonic level sensors are used for non contact level sensing of highly viscous liquids as well as bulk solids.