1. Product introduction
1.1 Product introduction
This product is a sensor that measures the velocity and flow of water in natural waters, channels, or pipelines.
The flowmeter is divided into two parts: the sensor and the host, and the middle is connected by a cable.
It can measure the speed and flow of water in channels and rivers, and the water level is more than 20 cm higher than the sensor.
It can measure the speed and flow of water in pipes and culverts. The water level must be more than 20 cm higher than the sensor, and the inner diameter of the pipe must be ≥ 500 mm.
1.2 working principle
The sensor has two transducers, one for transmitting and one for receiving. When the sensor is facing the direction of water flow, that is, under the premise of countercurrent measurement:
1. When the water flow is still, the received frequency is the same as the transmitted frequency.
2. The faster the flow rate, the faster the frequency received by the receiving sensor, which will be higher than the transmitting frequency.
3. The slower the flow rate, the slower the frequency received by the receiving sensor, but it will be higher than the transmitting frequency.
When the sensor measures along the direction of the water flow:
1. When the water flow is still, the received frequency is the same as the transmitted frequency.
2. The faster the flow rate, the faster the frequency received by the receiving sensor, but it will be lower than the transmitted frequency.
3. The slower the flow rate, the slower the frequency received by the receiving sensor, but it will be lower than the transmitting frequency.
From the above, the water flow velocity and direction can be calculated through hardware and software.
The sensor must be directly facing the direction of water flow during installation and use.
1.2 Technical parameters
Model abbreviation: HFT-DPLMQLS
Structure: split type;
Measurement types: velocity, flow, water depth, water temperature
Protection level: IP68
Purpose: online measurement
Flow rate range: ±0.03m/s～±5m/s (can be customized ±0.03m/s～±10m/s);
Water depth range: 0.02～3m, 0.02～10m (please confirm the maximum water depth before ordering);
Flow velocity accuracy: ±1% (detection accuracy submitted by the Ministry of Water Resources);
Flow velocity accuracy: ±1～3% (measurement accuracy will change due to the influence of on-site working environment);
Water depth accuracy: ±3cm;
Flow rate resolution: 1mm/s;
Temperature resolution: 0.1℃;
Water depth resolution: 1mm.
Flow range: 10 liters/sec～99999999 cubic meters/hour
Power supply: battery powered, 12VDC;
Output signal (battery powered): RS485;
RS485 output signal content: flow rate, instantaneous flow, cumulative flow, water level, temperature
Output signal (external power supply): 4-20mA;
4-20ma output signal content: instantaneous flow
Cable length between sensor and transmitter: 10 meters;
Types of tested waterways: pipes, channels, natural streams, rivers;
Liquid pH requirements: PH value is between 6 and 8, non-corrosive to the sensor.
Liquid temperature requirement: 0～60℃ (non-icing state);
Liquid pressure requirement: 1 standard atmospheric pressure in natural environment
The power supply for the flowmeter is 11～14VDC, and the power supply current is 250mA.
Continuous working power consumption: 14V×250ma=14V×0.25A=3.50W.
Supporting software: (optional)
Data acquisition system 1 set of low-power GPRS wireless data acquisition and transmission software
Integrated management system 1 set of low-power GPRS wireless data acquisition server software
1.3 Standard measurement status
After the power is turned on, the flow rate and flow rate will be output after 60 seconds, and then a data will be output every 3-5 seconds.
In the standard measurement state, the sensor directly outputs 485 signals to connect with the host, and the host outputs two kinds of data: flow rate and flow rate through the 485 interface.
