HSW Float-Type Water Level Sensor

Instrument Structure and Working Principle:

This instrument consists of a float, steel cable, counterweight, measuring wheel, sensor, bracket, output socket, and other components.

The working principle is as follows: the instrument uses a float to sense changes in water level. During operation, the float and counterweight are securely connected to the steel cable, which is suspended in the "V"-shaped groove of the water level wheel. The counterweight serves to tighten the steel cable and maintain balance. Adjusting the float's ballast allows it to operate at the normal draft line. When the water level remains unchanged, the forces on both sides of the float and counterweight are balanced. When the water level rises, the float generates upward buoyancy, causing the counterweight to pull the steel cable and rotate the water level wheel clockwise, increasing the reading on the water level sensor. When the water level falls, the float sinks, pulling the steel cable and rotating the water level wheel counterclockwise, decreasing the reading on the water level sensor.

The water level wheel of this series of water level sensors has a circumference of 32 cm, and the water level wheel is coaxially connected to the sensor. For every full rotation of the water level wheel, the sensor also completes one rotation, outputting 1024 corresponding sets of digital codes. As the water level rises or falls, the sensor's shaft rotates by a certain angle, and the sensor synchronously outputs a corresponding set of digital codes (binary cyclic code, also known as Gray code). Instruments of different ranges can output 65,535 different sets of codes, enabling the measurement of water level variations ranging from 10 to 20 meters.

The encoded signals can be transmitted via a multi-core cable connected to the instrument socket to an electronic display or computer in the observation room for monitoring, recording, or data processing. Water level gauges equipped with an RS485 digital communication interface can be directly connected to communication devices or computers, forming part of a hydrological automatic monitoring and reporting system or a hydrological satellite telemetry system.

The instrument's built-in RS485 digital communication interface (optional) features address selection and gating functions, enabling long-distance information transmission via a two-wire system. A single pair of twisted signal wires can drive or receive signals from multiple water level (or gate position) sensors, facilitating remote telemetry networking.