Product Introduction
LJ20 series propeller type current meter is a conventional universal instrument for measuring the flow rate in hydrological measurement. It is used to measure the average flow rate of a period of time at a predetermined measuring point in a river, lake, reservoir, channel and other water flow sections, and also can be used to measure the flow rate in pressure pipelines and some scientific experiments.
The LJ20 series rotary propeller flow meter complies with relevant national standards such as GB/T11826-2002 "Rotary Flow Meter".
The LJ20 series rotary propeller flowmeter is widely used in hydrological testing, water conservancy investigation, farmland irrigation, runoff experiments, etc. It can also be applied to industries or departments such as hydropower, environmental protection, mining, transportation, geology, scientific research institutes, municipal engineering for monitoring relevant flow velocity or flow rate.
Main technical performance and parameters
1. Rotating diameter of propeller: Φ125mm
2. Hydraulic pitch of propeller b: 200mm (theoretical value)
3. Starting speed v0: 0.03m/s
4. Critical speed vk: about 0.13m/s
(The actual verification value shall prevail. According to statistical analysis, vk is much smaller than the above value.)
5. Speed measurement range: 0.04m/s～10m/s
6. Output signal: Magnetic switch contact on/off signal
7. Signal number/rotor speed: 1/20 (LJ20A type) (1 signal every 20 revolutions)
1/1 (LJ20C type) (1 signal per 1 revolution)
8. Capacity of switch contacts: DC U≤24V
I≤120mA
9. Service life of switch contacts: ≥ 107 times
10. Relative mean square error of the entire line m:| M | ≤ 1.5% (for v ≥ vk)
11. Relative error δ:| δ | ≤ 5% (used when v<vk)
12. Working water environment: water temperature ranging from 0 ℃ to+40 ℃
Water depth ranging from 0.2m to 100m
Suspended sediment concentration ≤ 100kg/m3
13. Continuous working time: ≤ 12h
14. Storage environment: Temperature -25 ℃ to+55 ℃
Humidity ≤ 90% RH
