Burkert is launching a new addition to its flow measurement range. The Type 8081 is an ultrasonic flow transmitter that offers the major operating advantage of using no moving parts. This means that it is less affected by dirty media than other flow measurement devices for water. In addition, the 8081 has a wide dynamic measurement range, has a low pressure drop, and does not require long flow-conditioning tubes before and after its inlet and outlet.
With a brass body, the 8081 flow transmitter is intended for the measurement of water flows that may be lightly charged with contaminants. The design of the device delivers 'swirl-free' flow, which results in homogeneous velocity distribution; consequently, no inlet and outlet zones are required with the 8081 unit. Moreover, because the flow over the reflector surface is optimised in the 8081 design, the settling of dirt particles is prevented. This means that the device is non-sensitive to coating as a result of particulate build-up, which is a feature that ensures long-term stability and high reliability from the transmitter.
The 8081's measuring system is based on the well-proven Transit Time principle, with two piezoelectric ultrasound transducers that operate with both the downstream and upstream flow through the device. When the signal is against the flow its propagation time is longer compared with the downstream signal. The difference in travelling time between these signals is directly proportional to the flow speed and is used to calculate the volume flow.
There is a choice of five sizes, for pipe diameters from DN15–25, and flows from 0.06l/min up to a maximum of 200l/min. Depending upon the version chosen, the transmitter features either a pulse output or a pulse output and a 4–20mA current output; electrical connection is via a five-pin M12 fixed connector
The measuring facility provided by the 8081 can be extended and systemised by complementary products from Burkert, including: the Type 8611 PI Flow Controller; the Type 8032 remote flow transmitter; the Type 2712 and Type 6223 process control and solenoid valves, and also third-party PLCs.