River channel flow meter

River channel flow meterWorking Principle:

When Hangzhou open channel flowmeter is used for channel flow measurement, a measuring tank weir is installed on the channel. The function of a water measuring weir is to convert the flow rate in the channel into the level of liquid. Measure the liquid level inside the tank with a level gauge, and use a flow converter (secondary meter) to calculate the liquid flow rate based on the liquid level flow relationship of each type of tank.

The larger the flow in the channel, the higher the liquid level in the trough and weir; The smaller the flow rate, the lower the liquid level. There is no definite correspondence between liquid level and flow rate in general channels. Because the same water depth and flow rate are also related to the cross-sectional area, slope, and roughness of the channel. Installing a weir in a channel, due to the smaller gap or contraction of the weir compared to the cross-sectional area of the channel, the correspondence between the upstream water level and flow rate of the channel mainly depends on the geometric dimensions of the weir. The same weir is placed on different channels, and the same liquid level corresponds to the same flow rate. The weir converts the flow into liquid level.

River channel flow meterProduct Features

Adopting digital signal processing technology, suitable for applications in harsh environments.

*The signal environment display (oscilloscope technology) is easy to debug and install.

High speed and reliable microcontroller processing, fast and stable.

Multi data filtering technology ensures stable and reliable measurement.

16 bit high-precision D/A output improves the accuracy of 4-20mA output.

Equipped with a 485 interface, it can be connected to computers or other data collectors.

Technical parameters of ultrasonic open channel flowmeter

1. Flow range: 0 liters/second to 10 cubic meters/second (determined by the type and specifications of the measuring weir used)

2. Accumulated traffic: 12 decimal digits, automatically returns to zero after accumulation

3. Flow accuracy: 1.0%, 2.5%

4. Distance measurement range: 3 meters

5. Distance measurement accuracy: 0.25%

6. Liquid level resolution: 1 millimeter

7. Working environment temperature: -20~55 ℃

8. Instrument protection level: Instrument display part: IP65; Probe section: IP65

9. Power supply: AC power supply 220V ± 10% 6W

10. Instrument calendar clock timing error:<2 minutes/month

11. Instrument data storage capacity: stores 128 records of hourly flow, 64 records of daily flow, 32 records of monthly flow, 4 records of annual flow, and 64 records of power outages. Memory recycling, overwrite the earliest record when full

12. 4-20mA current output:

External load resistance: 0-500 Ω

Error margin: 0.1% (relative to instrument reading)

The negative terminal is connected to the instrument ground terminal (can be changed to suspended ground output according to application requirements)

Output content: Instantaneous traffic

13. RS485：

Encoding method: 1 start bit, 8 data bits, 1 stop bit

Baud rate: 9600

00-09, when set to 00, it will output once every measurement

When the address is 01-09, the command needs to be used to query:

The sending format is:! X (x is the address)

Return format: # 000000 0000.000; *The group data is cumulative flow (cubic meters), and the second group data is instantaneous flow (cubic meters/hour), separated by a space symbol.

14. Relay:

Control mode: Close once per accumulated set m3 (50 milliseconds), liquid level upper limit alarm

Type: Single pole double throw (normally open, normally closed) Contact capacity: AC250V 1A; DC30V 1A