Current flowmeter

1. Product introduction of flow rate flow meter

The flow meter is also called a portable river reservoir flow meter or a portable flow meter . The flow meter is a portable hydrological flow meter that is used to measure the average flow rate at predetermined measuring points in rivers, lakes, reservoirs, canals, etc. Measurement.

The flow rate meter complies with relevant national standards such as GB/T 11826-2019 (rotor flow meter).

The flow rate 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.

The flow rate flow meter mainly consists of a propeller flow rate sensor, a flow rate calculator, and a 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. Technical parameters of flow rate flow meter:

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

Propeller rotation diameter: Ф125mm

Propeller hydraulic pitch b: 200mm (theoretical value)

Starting speed V0:0.03m/s

Speed measurement range: 0.04-10.00 m/s

Flow measurement error: ≤1.5%

Output signal: magnetic switch contact on-off signal

Number of signals/number of rotor revolutions: 1/20 (LJ20A type) (1 signal every 20 revolutions); 1/1 (LJ20C type) (1 signal every 1 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. Measurement principle of flow rate flow meter:

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.