Model DRT fl owmeters utilise the widely accept-ed oscillating piston design principle with the performance enhanced by the use of modern engineering materials to pro-vide a cost effective and reliable solution for a wide range of industrial fl ow measurement applications.
This fl owmeter utilises the oscillating piston principle, where the passage of liquid causes a piston to oscillate smoothly in a circular motion inside a round measuring chamber. Each piston cycle displaces a known volume of liquid from the inlet port to the outlet port. Small high energy magnets located within the piston activate the integral electronics which in turn generate high resolution pulse outputs suitable for remote fl ow integration instruments, computers and PLC's.
This simple and robust design offers the advantage of only one moving part with both high resolution NPN Hall Effect open collector and reed switch outputs as standard. As each piston oscillating cycle passes a known volume of liquid, the inherent repeatability of the positive displacement fl owmeter makes it particularly suited to batching and dispensing du-ties.
Positive displacement fl owmeters are an inexpensive means to accurately meter high viscosity clean liquids as high as 1 million centipoise however, the appropriate meter must be sized so that the pressure drop across the primary measu-ring elements (oscillating or oval rotor), does not exceed the maximum capability of either. The oscillating piston meter can withstand 2.8 bar differential pressure making it more suitable to high viscosity liquids, the oval wheel is limited to 1 bar diffe-rential due to the pressure imposed on the rotor shafts.