Flow meter

1. Flow meter product introduction

Flow meter is developed for hydrographic surveyors to measure velocity and flow. It can be used to measure velocity, flow in open channel and flow in pumping station.Flow meter (portable flow meter for short) is a universal instrument for measuring flow velocity in hydrological tests. It is used to measure the average flow velocity at predetermined measuring points in rivers, lakes, reservoirs, canals and other water-crossing sections.

Flow meter complies with GB/T 11826-2019 (rotor flow meter) and other relevant national standards.

Flow meter is widely used in hydrological tests, water conservancy surveys, farmland irrigation, runoff experiments, etc. It can also be used in hydropower, environmental protection, mining, transportation, geology, scientific research institutes, municipal administration and other industries to monitor related flow rates or flows.

Flow meter is mainly composed of LS1206B propeller flow velocity sensor, flow velocity calculator, and 0.4m×4Ф16 measuring rod. The complete set of instruments is placed in a high-grade aluminum alloy password box. By connecting the signal line, the flow rate in each open channel can be measured and the flow rate will be automatically displayed.

The instrument has a simple structure, is lightweight and convenient, consumes less power, has complete functions, has a high degree of automation, is stable and reliable, and complies with the national open channel flow measurement standards. It is equipped with a 60-degree high-temperature propeller. It is a new type of portable flow velocity measuring instrument in China.

2. Flow meter technical parameters:

Speed measurement formula: V＝KV/T＋C(m/s) (automatic calculation)

Propeller rotation diameter: Ф70mm

Propeller hydraulic pitch b: 120mm (theoretical value)

Starting speed V0:0.05m/s

Speed measurement range: 0.06-8.00 m/s

Flow measurement error: ≤1.5%

Output signal: magnetic switch contact on-off signal

Number of signals/number of rotor revolutions: 2/1 (2 signals per revolution)

Display: 4×16-bit LCD display

Measurement method: Measuring pole positioning measurement (cable suspension positioning measurement is also available)

Temperature range: -25℃-55℃, humidity ≤90%RH

Power supply: DC8.4V (rechargeable battery), can work continuously for more than 40 hours after full charge

3. Flow meter measurement principle:

This instrument is designed based on the flow velocity area method principle of open channel flow measurement. By measuring the flow velocity, the flow rate can be obtained Q=V·S (S is the cross-sectional area)

1.Flow velocity measurement:

When measuring the flow rate, the propeller-type rotor flow meter is driven by hydraulic power to rotate, and the built-in signal device generates a revolution signal. The flow rate is calculated by the following formula: V=KN/T+C (m/s) (automatic calculation)

V: average flow velocity during the flow measurement period (m/s)

K: Blade hydraulic pitch

C: flow meter constant

T: flow measurement duration (unit: S)

N: Number of signals in T period

When this instrument is used, K and C are constants. When measuring flow, as long as T and N are measured, the flow rate can be calculated.

2. Calculation of flow rate:

Flow measurement is based on the velocity area method of open channel flow measurement. The flow rate is measured first and then multiplied by the cross-sectional area to obtain the flow rate.