Portable Velocity Current Meter with 24 Hours Continuous Working

HT Handheld Reader

I. HT-A Type Handheld Reader

1. Introduction

Portable current velocity meter is an equipment used in water conservancy for velocity flow measurement, designed for hydro-logical stations,mining factories, environment monitoring stations, farm irrigation, hydro-geology and so on. Portable current velocity meter is composed of propeller velocity meter, HT type handheld reader and measuring bars. Full set of instruments is in the aluminum-alloy box.When using, you can assemble it as a body and connect the signal cable, then the velocity of every open channel can be measured. And it can automatically display the velocity and present the flow of sectional areas.

The instrument is ligHL and convenient with simple structure. It has low power consumption, complete function, high automation degree, stability and reliability, which complies with the national measurement standards.

2. Principle

This instrument is designed based on the theory of areas of open channel’s velocity. After measuring the velocity, the flow can be: Q=V·S(S is sectional area)

(1) Velocity Measurement

When measuring velocity, propeller velocity meter will be pushed by water power. The built-in signal apparatus produces RPM signal. The formula below can calculate velocity:

V: the average velocity(m/s)

B/K: the water power pitch of blades

C/a: velocity constant

T: lasting time(s)

N: the number of signal is T time

K/b and C/a are constants

Q: Flow

Remarks: When measuring, you can set T and then measure N, so the velocity and flow can be automatically calculated.

(2)Flow Calculation

The measurement of velocity is based on the theory of areas of open channel’s velocity. First, you can measure velocity and then multiply sectional area, so the flow can be gotten.

3. Specification

• Screen: 2*16 liquid crystal display
• Measuring method: Positioning measuring bar or suspended cable
• Temperature range: -10℃~45℃
• Communication: RS232
• Instrument calculation: Automatic calculation
• Power supply:5VDC,it can work for 40 hours after full power

II. HT-B Type Handheld Reader

1. Introduction

Portable current velocity meter is an equipment used in water conservancy for velocity flow measurement, designed for hydro-logical stations,mining factories, environment monitoring stations, farm irrigation, hydro-geology and so on. Portable current velocity meter is composed of propeller velocity meter, HT type handheld reader and measuring bars. Full set of instruments is in the aluminum-alloy box.When using, you can assemble it as a body and connect the signal cable, then the velocity of every open channel can be measured. And it can automatically display the velocity and present the flow of sectional areas.

The instrument is light and convenient with simple structure. It has low power consumption, complete function, high automation degree, stability and reliability, which complies with the national measurement standards.

2. Principle

This instrument is designed based on the theory of areas of open channel’s velocity. After measuring the velocity, the flow can be: Q=V·S(S is sectional area)

(1)Velocity Measurement

When measuring velocity, propeller velocity meter will be pushed by water power. The built-in signal apparatus produces RPM signal. The formula below can calculate velocity:

V: the average velocity(m/s)

B/K: the water power pitch of blades

C/a: velocity constant

T: lasting time(s)

N: the number of signal is T time

K/b and C/a are constants

Q: Flow

Remarks: When measuring, you can set T and then measure N, so the velocity and flow can be automatically calculated.

(2)Flow Calculation

The measurement of velocity is based on the theory of areas of open channel’s velocity. First, you can measure velocity and then multiply sectional area, so the flow can be gotten.

HL-B can automatically calculate the flow. At the same time, it can store 99 measured data.

3. Specification

• Screen: 2*16 liquid crystal display
• Measuring method: Positioning measuring bar or suspended cable
• Temperature range: -10℃~45℃
• Communication: RS232
• Instrument calculation: Automatic calculation
• Power supply:5VDC,it can work for 40 hours after full power
• Data storage: 99 articles
• Enclosure material: ABS
• N.W.:Appox.1.0kg

• Propeller Velocity Meter

I. LS20B Type Propeller Velocity Meter

1. Introduction

LS20B Type Propeller Velocity Meter had passed the technical appraisal appraise of the Ministry of Water Resources of the People’s Republic of China in 1986 and its performance had reached international advanced level of similar products. This product was awarded the Third Prize of Science and Technology Progress by the Ministry of Water Resources of the People’s Republic of China in 1988 and was honored as China state level new product in 1990. In 1993, it participated in the international flow meter test which was organized by United States Geological Survey(USGS) and its superb performance was well praised by American experts when compared with world famous brands such as American Price AA, Germany Occt-3, Britain Valeport BFM002 and so on.

2. Application

LS20B Type Propeller Velocity Meter is a kind of large-range hydro-logical flow meter, which is applicable to measure high, medium, and low flow rate of rivers, lakes, channels, reservoirs and so on. It can also be used for measuring high velocity or ultrahigh velocity flow rate in pressure pipe of power station and some scientific experiment.

3. Features

• Especially extensive velocity measurement range, one propeller can satisfy different measurement requirements.
• Good sealing performance makes regular work in operational condition of high velocity and high sediment concentration possible.(Highest measurement velocity is 4.3m/s, highest sediment concentration is 100kg/m³)
• The propeller adopts imported high quality engineering plastics, which is of high impulse strength, stable geometry, and aging resistance. The docimasy coefficient K won’t change in harsh natural condition environment.
• Low velocity performance and internal friction characteristics.
• Flexible installation manner and reasonable directional device structure can be suitable for current direction.
• Good structure intensity makes installation and support firm and can stand 15m/s high flow rate impact.
• Steam-line overall and built-in type empennage counter weight reduces water resistance. No additional deflection moment.

4. Specification

Velocity range:0.05~15m/s

Turning propeller diameter: Ø120mm

Propeller hydraulic pitch: H=200mm

Depth range: 50m

Measuring bar: Ø20mm*3.0m(can be discharged into three sections)

Signal frequency: two signals/rotation

Working temperature: 0-40℃

Verification formula relative deviation: ƍ<±1.5%(V≥V_k); ƍ<±5.0%(V<V_k)

Suspended Sediment Concentration: ≤50kgs/m³

Continuous working time: 24 hours

Switch contact capacity: current≤50mA, voltage≤6V

Material: Direction Indicator & Tail: ABS

Others: stainless steel SS304

N.W.:Appox.1.0kgs