Water Level Measurement System with Gray-Coded Linear Encoder

Budhi Anto, Tutut Herawan, Dian Yayan Sukma, Suwitno .


An application of linear encoder for water level measurement is introduced in this paper. The linear encoder consists of the scale which is a thin bar made of acrylic sheet and the detection unit consisting of light emitters and light detectors clamps closely the scale. The scale moves up and down together with variation of water level while detection unit is kept stationary. The detection unit encodes displacement of the scale into unique Gray coded digital data. The proposed measurement system is designed to measure level variation of water surface up to 1 meter with 0.01 meter resolution. This is implemented by division of the scale into 7 parallel tracks and deviding the tracks with 100 equal length segments. The output of linear encoder in the form of 7-bit Gray coded digital data is preconditioned prior connected to ATMEGA8535 microcontroller for processing and then the measurement result is displayed on LCD. The prototype of measurement system is successfully tested in the laboratory where some samples of measurement reading are also shown for clarity. The proposed measurement system can be further developed to measure higher variation of water level by lengthening the scale and increasing number of tracks and segments. 

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