Flow meter

1.Flow meter product introduction

Flow meter is a very important high-tech instrument in water flow field measurement, which has been widely used in the field of flow measurement in hydrological industry.Flow meter (portable flow meter for short) is a general instrument for measuring flow velocity in hydrological tests. It is used to measure the average flow velocity over a period of time at predetermined measuring points in water sections such as rivers, lakes, reservoirs, and canals.

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

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 relevant flow rate or flow.

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

The instrument has a simple structure, is lightweight and convenient, consumes little power, has complete functions, is highly automated, stable and reliable, complies with national open channel flow measurement standards, and 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 excitation switch contact on/off signal

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

Display: 4×16-bit LCD

Measuring method: measuring rod positioning measurement (cable hanging positioning measurement is also possible)

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

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

3. Flow meter measurement principle:

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

1. Flow rate measurement:

When measuring flow velocity, the propeller rotor flowmeter is driven by hydraulic power to rotate, and the built-in signal device generates a rotation signal. The flow velocity 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: hydraulic pitch of propeller blades

C: Flow meter constant

T: flow measurement duration (in seconds)

N: Number of signals in T period

When the instrument is in use, K and C are both constants. When measuring flow, the flow rate can be calculated by simply measuring T and N.

2. Flow calculation:

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