1、 Equipment composition

2、 Equipment principle

The principle of ultrasonic open channel flowmeter is to directly measure the liquid level in conjunction with a measuring weir, and to convert the liquid level depth through the corresponding liquid level flow conversion relationshipconvertMeasure the flow rate in the water tank. The higher the liquid level in the measuring tank, the greater the flow rate; conversely, the lower the liquid level, the smaller the flow rate. The measurement principle is shown in the following figure:

The ultrasonic transducer is installed above the upper water tank to measure the water level depth of the overflow water tank, and the water level depth is input into the flow conversion formulaThe formula isFlow out. The geometric parameters in the calculation formula for different groove types are also different, so it is important to pay attention to setting all parameters of the groove type when using it.

3、 Application scope

Ultrasonic open channel flow meters are mainly suitable for small channels with relatively large channel slopes (within 1 meter). It supports flow calculation for three types of open channel measuring weirs: right angled triangular weirs, rectangular thin-walled weirs, and Bacher troughs. The flow can be accumulated according to the set conditions, for example, if the accumulated low water level is 0.05 and the accumulated high water level is 1, the flow can be accumulated when the water level is greater than 0.05 but less than 1.
When selecting a standard Bacher slot, the effective head range of the corresponding slot type will be automatically loaded. When choosing the type of measuring weir, consideration should be given to the flow rate inside the channel, the flow state of the water in the channel, and whether free flow can be formed. When the flow rate is less than 40L/s, a right angled triangular weir should generally be selected. For speeds greater than 40L/s, it is generally recommended to use a Bacher slot. If the flow rate is greater than 40L/s and the water level drop in the channel is large, a rectangular weir can be chosen. If conditions permit, it is best to choose the Bacher groove. The water level flow relationship of the Bacher Trough is calibrated experimentally, and there are relatively weak requirements for the upstream channel conditions. The water level flow relationship of triangular and rectangular weirs comes from theoretical calculations, which can easily lead to additional errors due to neglecting some usage conditions.

4、 Equipment installation

The ultrasonic sensor is equipped with a fixed screw ring, and installation holes are reserved in advance at the installation position. After placing the ultrasonic sensor in place, tighten the screw ring.Connect the host and ultrasonic sensor as required. During installation, pay attention to keeping the sensor end face perpendicular to the bottom of the weir groove, and there should be no obstructions within the measurement range of the sensor.After installation, enter the installation height (Bacher is the distance from the end face of the ultrasonic transducer to the bottom of the weir, rectangular weir and right angled triangular weir are the distances from the end face of the ultrasonic transducer to the lowest outlet of the weir), set the geometric parameters of the weir, and it is ready for operation.If the data still fluctuates significantly, a waveguide with a diameter of can be installed at the front end of the ultrasonic sensor100Millimeters, with length exceeding the edge of the weir groove. The waveguide can be made of a smooth inner wall seamless water pipe, with the front end cut into one45Angle of inclination. Its shape and installation method are shown in the figure:

5、 Characteristics

1. Non contact installation can prevent sedimentation;

2. Only measures water level, with less environmental interference and good stability;

3.Micro power design, battery powered for continuous use6 months;

4. Low price.

1. Cumulative traffic range: 0~9999999 (reset to zero when 8 digits are reached, and the cumulative number of times is increased by 1. The traffic unit is set according to the setting);
2. Instantaneous flow range: 10L/s to 10m3/s (determined by the type and specifications of the measuring weir tank used);
3. Traffic accuracy: 5%;
4. Probe ranging range: 2m, 5m, 8m, 10m (2m is standard, and high-precision can be selected according to on-site conditions)
Small blind spot type can also choose a larger number of process types);
5. Probe blind zone: 0.1-1.5m (different from the range);
6. Distance measurement accuracy: ± 0.25% F.S (depending on the probe);
7. Display: Chinese 3-inch LCD;
8. Liquid level resolution: 1mm;
9. Keyboard: 16 bit keyboard operation;
10. Signal input: transducer (standard), 4-20mA, 0-20mA, 1-5V, 0-5V, RS485;
11. Optional signal output: one or two 4-20mA channels (standard configuration includes one 4-20mA channel, only one channel is available for transducer input) ）The
RS485/232 (supporting Modbus protocol) (standard), 4-channel relay output
(Relay contact capacity: AC: 5A 250V DC: 10A 120V) (optional);
12. Working voltage: AC220V or DC12-24V;
13. Power consumption:<3W;
14. Instrument material: The host material is ABS, and the sensor material is ABS;
15. Overall dimensions of the host: 240mm × 184mm × 110mm;
16. Sensor dimensions: Φ 65mm × 119mm × G1 1/2 (2m range), Φ 74mm × 137mm × M60
(5-15m range), Φ 109mm × 194mm × M30 (20-30m range);
17. Sensor installation interface: G1 1/2 (2m range), M60 × 2 (5-15m range), M30X (20-30m range);
18. Sensor cable: 10m shielded cable (customizable to any length);
19. Working environment: normal temperature and pressure;
20. Protection level: Host protection level IP53, sensor protection level IP67 (optional higher protection level);
21. Data browsing: Quickly view hourly, daily, monthly, and annual traffic records;
22. Optional functions: Supports MiniSD card data acquisition, wireless transmission, and micro printers.