Specifications and Product Details:

Principle

By using digital signal processing techniques, DMDF-OP-B is able to perform in a wide range of environments. It is used to record flows in pipes, channels and small streams and operates in a wide range of water qualities from fresh streams to primary sewage channels.

Velocity Measurement

When sound is reflected from a moving target, the frequency of sound is varied by the velocity of target. This variation is known as a Doppler shift. To measure water velocity in open channels/pipes, DMDF-OP-B exploits the particles moving with the water as acoustic targets (or scatterers) from an instrument fixed to the bed, bank or bottom. Each Doppler shift is directly related to the water velocity component along the beam. This is a physical relationship and if you know the speed of sound in water you can calculate the velocity of the reflector and thereby the velocity of the surrounding water.

Level Measurement

Water level is measured using a solid state pressure sensor mounted underneath the DYNAMETERS transducer and vented to atmospheric pressure via a vent tube inside the signal cable. Water pressure is sensed via a pressure damping manifold which has been designed to sense level in front of the velocity transducer.

Flow Rate Calculation

The flow formula: Q=V·A

Where V——Fluid velocity

A——Cross-sectional area of liquid

A is the function of liquid level and width of channels or inner diameter of pipes, A=f(D·h)

Where D——Width of channels or inner diameter of pipes

h——Liquid level

Features

1.For Open Channel and Partially Filled Pipe applications

2.Excellent low flow rate measurement ability, low to 0.021 m/s

3.Superior measurement accuracy

4.4-20mA and RS485/MODBUS output, GPRS is optional

5.Very suitable for sewage measurement

6.User-friendly configurations

7.Complete in specifications, and can provide a variety of applications

DMDF-OP -B Flow Meter includes flow calculator, DYNAMETERS velocity and level transducer.

The flow calculator can set the calculate the cross-sectional area of partially filled pipe or open channel, for circular pipe, it only need to input the inner diameter; for open channel, it is suitable for various measuring situations, users can input up to 20 point coordinates of channel to calculate the cross-sectional area.

The flow calculator can display the velocity, level, flow rate and flow totalizer, and is configured with 4-20mA and RS485/MODBUS output, GPRS is optional.

DYNAMETERS Velocity and Level Transducer

The instrument is intended for economically recording flows in channels, culverts and pipes. It can also be used where existing techniques are unsuitable or too expensive. It is particularly useful at sites where no stable stage/velocity relationship exists and where flows are affected by variable tailwater conditions, culvert entry blockages, pipe surcharging, other unstable flow conditions, or even reverse flows.

DYNAMETERS velocity and level transducer combines water velocity and water depth measurement with a powerful data logger.

DYNAMETERS velocity and level transducer is mounted on (or near to) the bottom of the stream/pipe/culvert and measures the velocity and depth of the water flowing above it.

When installing transducer, a hoop as shown above is needed, at first, fix the transducer on the hoop, then fix the component in the pipe, and connect the cable to flow calculator.