Yogyakarta-In certain cases such as anticipation of disaster programs, irrigation or hydroelectric power, data on the water surface elevation measurements are vital. However, water level measurement tools that exist today such as potentiometers and ultrasonic equipment is still not effective and can only be measured in a limited height. It inspires Asep Nurdiansyah, students majoring in Electrical Engineering University of Muhammadiyah Yogyakarta (UMY) to develop a gauge height of water surface by applying the Gray code which is more effective and has a wider measuring range.

"Measurement of water levels as a monitoring effort is felt very important lately. While the method of measurement (water level) with a ruler measuring is less effective. Other measuring tools that exist today also have many limitations," said Asep.

He added, Gray Code (encoder gray) technology implementation would minimize the possibility of the tool to wear out like the potentiometer. Gray encoder could also measure changes in water levels deeper than the ultrasonic equipment which was only capable of up to a distance of 160 cm.

"Additionally, with this tool, we can know directly changes of the height of water level through short messaging services sent to mobile phones without having to look to the location" Asep explained.

Asep further explained, in order to get water level data at a desired location, the tool he created was only to set on a buoy. Then it was just organized of when or how the condition for this tool to send short messages to our mobile phones. The setting could be a water height level at certain times or certain changes in water level.

"By using a battery as a power source, this tool does not need to be a source of electrical power sources so that more electricity can easily be placed anywhere," said Asep.

According to this student from Temanggung, his tool consisted of four main parts: sensors, processors, and transmission media viewer. The sensor used was a rotary encoder that are commonly used in robot control and motor drives. While the processor was applied to the Processing Unit ATMega162 Microcontroller. The display media was using LCD and transmission media was texting technology (Short Message Service) using GSM.

While the Gray code used as the central processor was a mathematical code that was introduced and patented by Frank Gray in 1947. The code also known as the reflected binary code was a binary numbering system in which two adjacent values ​​only had exactly one digit different.At first, Gray code was applied as a puzzle for mathematicians.

Asep admitted, at today's market there had been a kind of measuring device. Yet, the tools were imported product and the price was very expensive compared with his measuring device. He added that the tool was very suitable for monitoring ground water level or height of dam water. This homemade instrument could measure the height of water up to 6 meters.

Thanks to the guidance of Muhammad Helman, ST., MT and Ir. HM. Fathul Qodir as a tutor, the tool which was part of the final task was completed in about a month by Asep. (Www.umy.ac.id)