Open channel flow meter (Pakistani Erlang tank + ultrasonic level gauge) . Composed by a general intelligent open channel flowmeter flow display, a tank, bashir's a ultrasonic liquid level meter. Open channel flow meter is in the full open tubular channels to measure free surface natural stream flow meter. The full pipe flow state of water called open channel, known as the water flow in open channel flow in open channel measurement meter open channel flow meter in addition to the circular, and U, trapezoidal and rectangular shapes. A wide variety of open channel flow meter, common have weir open channel flow meter and slot open channel flow meter two kinds big.

Open channel flow meter based on ultrasonic liquid level meter to measure the actual water level and has been put into the channels of groove geometry size, slope coefficient, hydraulic slope, flow rate, channel precision vertical plane correction coefficient, according to the predetermined mathematical model to calculate the flow channels.

Open channel flow meter are applicable to all reservoir, river, water conservancy projects, urban water supply, sewage treatment, irrigation, take water such as rectangular, trapezoidal open channel flow measurement and culverts.

1.Large measuring range, flow measurement is not affected by the effect of surface water.

2.Measurement is not affected by the water when the floater of sediment, bubble and water level changes significantly affect the flow sensor on the flow resistance of simple structure, small volume, convenient installation.

3.Standard channel little or no modification can be installed directly, low cost of installation.

4.Instrument display output function is all ready, can according to water level, flow velocity, flow and integrated flow measurement data, and with the RS - 485 communication interface.

5.With water, mud, velocity transfinite alarm function.

6.With the function of data, it can save in the case of long-term power parameters and flow value.

Open channel flowmeter directly measured quantities is level. When used in open channel flow measurement, installation of measuring weir trough in open channel. Measuring weir tank in the open channel flow into the size of the liquid level of high and low. Meter measuring weir tank water level, and then according to the corresponding relationship between measuring weir tank water level - flow to calculate flow. Common in the open channel flow and the corresponding relation between the water level, affected by the channel slope ratio and surface roughness. Installation of measuring weir trough within the channel, the throttling effect, make the open channel flow and liquid level in a fixed corresponding relation. The corresponding relation mainly depends on the structure of the measuring weir tank size, to minimize the influence of the channel.

Meter, ultrasonic sensor installed in the measured liquid level above. Firing pulse ultrasonic probe into water. Sound waves through the air reaches the surface, sound waves by liquid surface reflection be reflected wave, probe receives the reflected wave is called echo. At the bottom of the probe calibration rods also produces reflection wave probe receives called calibration. Instrument according to the transmitted wave and echo, launch and correction wave between the time difference, distance and probe into the liquid surface. The distance with the probe to zero water level L, namely liquid level height H. As shown.

Open channel flow meter sensor installed on the measuring weir tank water level observation point position, water level of measurement through measuring weir tank. Fill in the corresponding  installation, the water flow measuring weir tank relationship via the buttons in the form of table load instrument internal storage. Instrument microprocessor by the measured water level, using look-up table method and the corresponding flow value. Table of the number between the two adjacent values, using linear interpolation method.

Water level (m) : measuring range 0 ~ 3.0 m;

Blind area (m) : 0.3 m;

The machine precision: system error of plus or minus 3 ‰;

The flow measurement range: depends on the weir/slot type, a maximum of 9999 m3 / h;

Working temperature (℃) : - 20 ℃ ~ + 60 ℃;

Minimum water level resolution (mm) : + / - 1 mm;

Signal output: RS485, 4 ~ 20 ma, 2 way switch output;

Measuring the velocity range: 0.02-20 m/s;

Channel width: 0.5-30 m;

Channel depth: 0.5-20 m;

Material: stainless steel;