LJ20A propeller flowmeter

The LJ20A portable flow meter is specially developed for measuring open channel flow velocity and flow in the field by hydrological stations, factories and mines, environmental monitoring stations, agricultural drainage and irrigation, hydrogeological surveys and other departments.

The portable current meter mainly consists of LJ20A propeller type current sensor, LS-A type current meter, and measuring rod. The entire set of instruments is placed in an aluminum alloy password box. When in use, assemble it as a whole and connect the signal line to measure the flow velocity in each open channel, and automatically display the flow velocity. The structure is simple, lightweight, convenient, energy-efficient, fully functional, highly automated, stable and reliable, and meets the national standards for open channel flow measurement.

Specification

1. Spiral propeller structure: spiral curved double blade, left-handed, PC plastic

2. Rotating diameter of propeller D: 120mm

3. Spiral propeller hydraulic pitch b: 200-250mm

4. Instrument starting speed Vo: ≤ 0.03m/s

5. Critical speed Vk of the calibration curve: about 0.13m/s (starting point of the straight line formula)

6. Flow velocity measurement range V: 0.03-10m/s

7. Signal component structure: Magnetic steel reed switch electronic switch

8. Number of revolutions per signal: 20 revolutions

9. When the relative error of the calibration curve E: V ≥ Vk, E<± 1.5%; When V<Vk, E<± 3%

10. Switch contact capacity: current ≤ 50mA, voltage ≤ 6V

11. Working life of reed switch: 70 million cycles

12. Continuous working time of the instrument: 40 hours (suspended sediment concentration ≤ 50kg/m3, flow velocity ≤ 5m/s, water depth ≤ 10m)

13. Instrument working water flow conditions: water depth range: 0.2m to 50m; Water temperature: 0-40 ℃; Salinity: ≤ 2g/L; Suspended sediment concentration: ≤ 10kg/m3

14. Display screen: 4 × 16 bit LCD display

15. Measurement method: Pole positioning measurement (also cable suspension positioning measurement)

16. Power supply: DC8.4V (rechargeable battery), can work continuously for more than 40 hours after being fully charged

Specification

1. Spiral propeller structure: spiral curved double blade, left-handed, PC plastic

2. Rotating diameter of propeller D: 120mm

3. Spiral propeller hydraulic pitch b: 200-250mm

4. Instrument starting speed Vo: ≤ 0.03m/s

5. Critical speed Vk of the calibration curve: about 0.13m/s (starting point of the straight line formula)

6. Flow velocity measurement range V: 0.03-10m/s

7. Signal component structure: Magnetic steel reed switch electronic switch

8. Number of revolutions per signal: 20 revolutions

9. When the relative error of the calibration curve E: V ≥ Vk, E<± 1.5%; When V<Vk, E<± 3%

10. Switch contact capacity: current ≤ 50mA, voltage ≤ 6V

11. Working life of reed switch: 70 million cycles

12. Continuous working time of the instrument: 40 hours (suspended sediment concentration ≤ 50kg/m3, flow velocity ≤ 5m/s, water depth ≤ 10m)

13. Instrument working water flow conditions: water depth range: 0.2m to 50m; Water temperature: 0-40 ℃; Salinity: ≤ 2g/L; Suspended sediment concentration: ≤ 10kg/m3

14. Display screen: 4 × 16 bit LCD display

15. Measurement method: Pole positioning measurement (also cable suspension positioning measurement)

16. Power supply: DC8.4V (rechargeable battery), can work continuously for more than 40 hours after being fully charged