The HSW series float type water level sensor is a digital sensor that integrates mechanical and electrical technology. There is a water level display on site, which converts the angular displacement of the output shaft into corresponding digital values, allowing for high-precision measurement of the measured liquid level height and confirmation of position. Equipped with power-off memory function. The working principle is that the water level sensor measuring wheel is installed on the input shaft of the encoder, and one end of the steel wire rope is connected to the float and the other end is connected to the heavy hammer. The steel wire rope is wound around the measuring wheel. When the liquid level changes, the float rises and falls with the change in liquid level, and the steel wire rope drives the measuring wheel to rotate. The encoder outputs the corresponding real-time water level value.

Technical Specifications:

1. Basic parameters

Measurement range: 0-5, 10, 20, 40, 80 meters as required;

B water level variability:<100 cm/min

C resolution: 1cm

D water level wheel starting torque:<100 g · cm (0.0098N · m)

F measurement accuracy: ≤± 2cm or 0.2% F · S

F display: decimal mechanical counter

2. Mechanical parameters

Working circumference of water level wheel: 32cm

Measurement cable: Φ 0.8mm stainless steel cable

Float diameter: 10cm

3. Electrical parameters

Output form: Contact on/off output Contact resistance: ≤ 0.5 Ω; Insulation resistance: ≥ 10M Ω

4. Communication interface (optional)

RS485 interface (MODBUS-RTU protocol);

Gray code output; 4-20mA current analog output;

5. Usage environment

Environmental temperature: -25 ℃~85 ℃

B Relative humidity; <95%(40℃)

C size: 132 × 132 × 115

Reliability index: MTBF ≥ 25000 hours under normal maintenance conditions of the instrument

E power supply voltage: 12-24VDC (Gray code output not required)

Working Principle:

Instrument structure and working principle:

This instrument consists of a float, steel wire rope, heavy hammer, measuring wheel, sensor, bracket, output socket, and other parts.

The working principle is that the instrument senses changes in water level with a float. In the working state, the float, heavy hammer, and steel wire rope are firmly connected, and the steel wire rope is suspended in the "V" - shaped groove of the water level wheel. The balance hammer tightens the steel wire rope and balances it, and adjusting the counterweight of the float can make it work on the normal waterline. When the water level remains constant, the forces on both sides of the float and balance hammer are balanced. When the water level rises, the float generates upward buoyancy, causing the balance hammer to pull the steel wire rope and rotate the water level wheel clockwise, resulting in an increase in the display reading of the water level sensor; When the water level drops, the float sinks and pulls the steel wire rope to drive the water level wheel to rotate counterclockwise, causing the display reading of the water level sensor to decrease.

The water level wheel of the mechanical water level sensor in this series of instruments measures a circumference of 32 centimeters, and the water level wheel is coaxially connected to the sensor. For every revolution of the water level wheel, the sensor also rotates once, and outputs 32 sets of corresponding digital codes. When the water level rises or falls, the axis of the sensor rotates a certain angle, and the sensor synchronously outputs a corresponding set of digital codes (binary cyclic codes, also known as Gray codes). Instruments with different ranges can output 1024 to 8192 different codes, which can be used to measure water level fluctuations from 10 to 80 meters.

The multi-core cable connected to the instrument socket can transmit the encoded signal to the electrical display or computer in the observation room for observation, recording, or data processing; The water level gauge installed with RS485 digital communication interface can be directly connected to the communication machine and computer to form a hydrological automatic measurement and reporting system and a hydrological satellite telemetry system.

The built-in RS485 digital communication interface (optional) of the instrument has location selection and gating functions, and can transmit information over long distances in a two-wire manner. It can drive or receive 31 water level (or gate) sensors on a pair of twisted pair signal lines, achieving telemetry networking.

Wiring relationship:

1. 485 interface (4-core aviation plug): 1-485a; 2-485b; 3- Power supply+; 4-GND。

2. Gray code interface (19 core aviation plug): 1-13 are data D0-D12, 19 is the common terminal.

3. Analog interface (6-core aviation plug): 1-485a; 2-485b; 3-4-20mA +； 4-4-20mA -； 5- Power supply+; 6-GND