LS10 flow meter, LS10 flow rate measuring instrument, LS full series flow meter

>summary
The LS10 propeller flowmeter is used to measure the time averaged flow velocity at predetermined measurement points in flowing water.
The characteristics of this instrument are small size, lightweight design, compact and precise structure, easy to carry and use. It is suitable for small rivers, shallow waters of large rivers, irrigation and drainage channels, water conservancy investigations, runoff experiments, etc. It is widely used for measuring the efficiency of small and medium-sized pump stations in pipe flow measurement and hydraulic machinery efficiency experiments, as well as for sewage monitoring and seepage flow measurement in environmental protection departments.

1、 Purpose:

The LS10 propeller flowmeter is a hydrological measurement instrument suitable for measuring the average velocity of water flow at predetermined measurement points in general rivers, channels, pipelines, culverts, etc., in order to determine the flow rate of the section.

2、 Main technical instructions

1. Speed measurement range: V=0.10~4.0m/s;

2. Working water depth: The actual water depth using a measuring rod should not exceed 1.2m;

If fixed on the lead fish with a suspension rod, the water depth is generally not greater than 24m;

3. Working water quality: freshwater (containing moderate minerals) or turbid water containing sediment;

4. Continuous working hours: ≤ 10h;

5. Starting speed of the instrument: V0 ≤ 0.08m/s;

6. Mean square deviation of the verification formula: m ≤ 1.5%;

7. The number of revolutions of the propeller between each second signal: 20 revolutions.

3、 Working principle and calculation method

The working principle of the LS10 propeller flowmeter is that when the water flow acts on the sensing element of the instrument, the propeller produces a rotational motion, and there is a certain functional relationship between its rotation rate "n" and the flow velocity "V", V=f (n), which is determined through experimental verification of the water tank. The experiment shows that when the flow velocity is above 0.1m/s, the calibration formula of LS10 propeller flowmeter is a linear relationship.

Each instrument calibration result is accompanied by the following calibration formula:

V=bn+a (corresponding to the original standard V=Kn+C)

In the formula:

V - Flow velocity (m/s);

N - propeller rotation rate, equal to the ratio of the total number of propeller revolutions N (N=20 times the number of signals) to the corresponding speed measurement duration T, i.e. n=N/T (1/s);

B - Hydraulic pitch (m) (corresponding to the original standard K);

A - Instrument constant (m/s) (corresponding to the original standard C).

The values of b and a are related to factors such as the pitch of the propeller and the frictional resistance of the support system. Therefore, these parts must be used and maintained carefully, otherwise it will affect the accuracy of the flow meter test.

According to regulations, the speed measurement duration T can be selected from two options: 100 seconds and 50 seconds. Generally, 100 seconds is chosen.