Water Level Measurement Using Capacitive Sensor

1 have described the design and implementation of a liquid level measurement system based on a remote grounded capacitive sensor.

Water level measurement using capacitive sensor. Capacitive sensor for water level detection has been fabricated. This sensor comprises a printed circuit board pcb with configuration of two interpenetrating comb electrodes. 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. 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.

With a capacitive sensing based solu tion no moving parts or sensors need to be in direct contact with the liquid to be measured. 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. 5 v pp3. A rod of stainless steel and a polytetrafluoroethylene ptfe insulated wire have been used for electrode of capacitive sensor.

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. When the tube is empty the space is occupied by air. When the tube starts to fill more and more of the space will be occupied by water.

Liquid level sensing is based on the theory of a ratiometric measurement using three sensors as shown in figure 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 and 0 010 m. Level the capacitance of the level electrode is proportional to the liquid height hw. Also capacitive sensor is a noncontacting device in the common usage.

Performing system calibration using labview software can help achieve higher accuracy. 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. It has to be as high as the maximum max allowed liquid level. The space between the tubes is the dielectric.

For d h 1.