Water Level Measurement Using Capacitive Sensor

The space between the tubes is the dielectric.

Water level measurement using capacitive sensor.

When the tube is empty the space is occupied by air. It has typically high impedance sensor particularly at low frequencies as clear from the impedance reactance expression for a capacitor. With a capacitive sensing based solu tion no moving parts or sensors need to be in direct contact with the liquid to be measured. Performing system calibration using labview software can help achieve higher accuracy.

2 2 liquid level capacitive sensing 16 2 2 1 liquid level coplanar plate capacitive sensors 16 2 2 2 differential and ratiometric measurement of liquid level 19 2 2 3 active shielding 21 2 2 4 out of phase liquid level technique 23 2 3 fdc1004 capacitance to digital conversion 25 2 4 i2c data transfer between mcu and fdc1004 26. Level the capacitance of the level electrode is proportional to the liquid height hw. A water level measurement using an interdigital capacitive sensor with low cost low energy good repeatability high linearity and ease of installation is proposed with a support of experimental results. 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.

A rod of stainless steel and a polytetrafluoroethylene ptfe insulated wire have been used for electrode of capacitive sensor. This sensor comprises a printed circuit board pcb with configuration of two interpenetrating comb electrodes. 5 v pp3. The capacitive level sensor has the 2 conducting plates in the form of 2 electrically isolated aluminium tubes a smaller tube in a larger tube.

Liquid level sensing is based on the theory of a ratiometric measurement using three sensors as shown in figure 2. Instead the liquid level is measured with a non contact capacitive sensor deployed externally to the reservoir. It has to be as high as the maximum max allowed liquid level. ε r eff 1 ε r 2.

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. When the tube starts to fill more and more of the space will be occupied by water. There are two types of capacitive level sensor contact type or non contact type for water level measurement. For d h 1.

Capacitive sensor for water level detection has been fabricated.