HP-L-01 Doppler Ultrasonic Open Channel Flow Meter

Scope of application

The flow measurement of channels or rivers is suitable for various water qualities: urban sewage, industrial wastewater, irrigation water, drinking water, and seawater.

Product Principle

The product has three functions: measuring average flow velocity, measuring water depth, and measuring water temperature.

1Water temperature measurement: The water temperature measurement uses a temperature probe, which is not in contact with water and is tightly attached to the top of the instrument's outer packaging material. It needs to be placed at the bottom of the water for a certain period of time to reflect the actual water temperature. The purpose of measuring water temperature is to calibrate the speed of ultrasonic waves in water and correct the water level value measured by the pressure sensor.

2Water depth measurement (cross-sectional area of water passage): Imported high-precision pressure sensors are used for water depth measurement, placed at the bottom of the instrument, and the sensing part of the probe is in direct contact with the water; After measuring the water depth, the cross-sectional area of the water passage can be obtained by measuring the cross-sectional shape of the channel section.

3Average flow velocity measurement: The measurement of flow velocity is obtained by emitting and receiving ultrasonic wave signals through an ultrasonic probe (transducer) and performing corresponding calculation processing1The transmission frequency isf1The ultrasonic signal is emitted from underwater at a certain angle towards the water surface. When it encounters suspended particles or bubbles in the water, the frequency shifts andf2The frequency is reflected back to the transducer2This is what Doppler will do,f2andf1The difference is the Doppler frequency differencefdLet the fluid flow rate bevThe ultrasonic velocity iscDoppler frequency shiftfdProportional to fluid velocityvThere will be a large number of impurity particles and bubbles in the water, and each reflected particle corresponds to a Doppler frequency shiftfdBy conversion, the flow velocity can be obtained, and the average flow velocity of these large particles is also the average flow velocity of the fluid.

By measuring the average flow velocity, water level, and cross-sectional size, the cross-sectional flow rate can be determined.

technical indicators

◆ Current Speed:

quantity Cheng:21mm/sto10000mm/s.

Accuracy: ± for measuring flow velocity2%.

Resolution:1mm/s.

◆ temperature

quantity Cheng:0℃ to60℃。

Resolution:0.2℃。

◆ Water level:

quantity Cheng:0.1to10m.

Resolution:1 mm.

Accuracy: ± for measuring water level1%.

◆ Traffic:

quantity Cheng:0.001m3/sto1000m3/s.

Resolution:0.0002m3/s.

Accuracy: ± for measuring flow rate3%.

◆ power supply12V DCor220VAC.

◆ Interface: StandardRS232TheRS485.

◆ Communication protocol:Modbus.

◆ Data storage capacity:

each10Collect one record per minute, which can be stored for more than6Months of data, and even in the event of a power outage, these data can be retained for a long time.

◆ Operating temperature:0℃ to60℃ water temperature.

◆ Shell material:pcplastic

◆ Size:

（250×105×35）mm(Probe).

（230×180×65）mm(Terminal).

10mThe standard length of communication cables can be extended to100 m）