DEVELOPMENT OF LASER DENSITOMETER

Sludge densitometers are used widely in the wastewater and sludge treatment plants. These measuring instruments are indispensable for the control of each treatment process. Many densitometers on various measuring principles are available in the market, but at present it is very difficult to find the panacea one that meets all the requirements of accuracy, stability, easy maintenance and reasonable price. For this reason it is desired to develop a new densitometer of accurate reading, free from any influence of the difference in sludge characteristics, easy maintenance and proper price. To meet these requirements, we participated in the operational study under the joint R & D program sponsored by the Tokyo Metropolitan Government and developed the sludge densitometer that utilizes laser beam.Then the prototype was designed and produced based on our study, adopting the newly developed optical system and the calculation method that converts an optical signal to a sludge concentration value. It proved an excellent capability in evaluation tests, which were carried out by installing it in sludge lines of sludge treatment plants.