LJ20 Type Propeller Current Meter

1. Product Introduction

This series of propeller current meters are conventional general-purpose instruments for velocity measurement in river hydrological surveys, used to determine the time-averaged velocity at predetermined measuring points in cross-sections of rivers, lakes, reservoirs, channels, and other water bodies.

This instrument complies with and meets technical standards such as GB/T11826-2002 "Rotor-type Current Meters".

2. Main Technical Specifications

(1) Propeller structure: A pair of left-hand helical curved blades, composed of a paddle column and a flow guide cap, made of PC plastic

(2) Propeller rotation diameter D: 125mm

(3) Propeller hydraulic pitch b: 200mm

(4) Instrument starting speed V0: 0.03m/s

(5) Calibration curve critical speed Vk: approximately 0.13m/s (starting point of the linear formula)

(6) Velocity measurement range V: 0.05～8m/s (experimentally calibrated Vmax=15m/s)

(7) Signal component structure: Magnet—reed switch electronic circuit

(8) Signal revolutions per pulse: 20 revolutions

(9) Calibration curve error: When V ≥ Vk, overall mean square error M ≤ ±1.5%;

When V < Vk, average relative error E < ±3%

(10) Switch contact capacity: Current ≤ 120mA, Voltage ≤ 24V

(12) Instrument continuous operation time: 2 hours (suspended sediment concentration ≤ 10kg/m³, velocity ≤ 5m/s, water depth ≤ 10m)

(13) Instrument operating hydraulic conditions

Water depth range: 0.2～50m; Water temperature: 0～40℃

Suspended sediment concentration: ≤ 50kg/m³

Salinity: ≤ 2g/