Bubble Type Water Level Gauge

Product Manual

The AN-BSR01 bubble type water level gauge is a high-precision water level sensor independently developed and manufactured by Annaien. It adopts a miniature piston pump as the air-blowing pressure guiding device. The hydrostatic pressure at the underwater measuring point is converted into gas pressure, which is transmitted above the water surface through a measuring tube and then detected and processed by a pressure sensor to realize water level measurement. Since the pressure sensor measures the pressure of compressed air without contacting the measured liquid, the device delivers excellent long-term stability.

Featuring high precision, high reliability, intelligent functions, no need for air cylinders or measuring wells, maintenance-free performance, vibration resistance and long service life, this product is ideal for flowing water bodies, rivers, reservoirs, heavily polluted water and highly corrosive industrial wastewater. It is widely applied in hydrology monitoring, upstream and downstream of dams, ocean and groundwater level measurement, petroleum, chemical industry, sewage treatment plants, urban drainage pumping stations and other scenarios where constructing measuring wells is inconvenient or costly.

External air is filtered and purified by an air filter before entering the air pump. The pump compresses the air to generate pressure, which flows rapidly to the air chamber via a one-way valve. The gas splits into two paths: one leads to the pressure sensor inside the pressure control unit, and the other goes into the underwater vent pipe.

When the air pump stops operating, the one-way valve closes and seals the outlet of the underwater vent pipe, forming a closed cavity connecting the pressure sensor and the pipe outlet. Pressure is uniform throughout the sealed cavity, so the pressure at the pipe outlet equals the pressure detected by the sensor. Subtract atmospheric pressure from the measured pressure to obtain the net water head, and the actual water level can be calculated after conversion and correction.

n Non-contact measurement with high precision, superior stability and easy maintenance.

n Simple installation, no measuring well required, free from interference of floating debris on water surface.

n Automatic zero calibration function to completely eliminate zero drift error.

n Supports external temperature sensor to compensate liquid specific gravity changes caused by temperature variation.

n Equipped with analog output and digital communication interfaces for flexible use.

n Wide voltage input design, with reverse connection protection, overvoltage & overcurrent protection and lightning surge protection.

n 4.3-inch full-color IPS touch screen for intuitive real-time data display and convenient operation.

n Automatic cleaning function to keep the vent pipe unobstructed.

n Built-in storage supporting up to 200,000 historical data records.

n Compatible with Modbus communication protocol for easy connection with various data acquisition devices.

Measuring Principle：Hydrostatic Pressure Method

Measuring Range：Optional: 20 m / 30 m / 40 m / 50 m

Resolution：1 mm

Accuracy Class：Class 1

Measurement Precision：0.03%FS

Repeatability Error：1 mm

Long-term Stability：≤±0.1%FS per year

Measuring Interval：1 ～ 60 minutes (adjustable, default: 1 minute)

External Temperature Sensor：Supported (optional accessory)

Measured Medium：Water (rivers, lakes, groundwater, etc.); Customized for special liquids

Display：4.3-inch IPS full-color touch screen, 480 × 800 resolution

Key：1 tactile key for screen wake-up and standby

Storage：16M built-in memory, max. 200,000 historical records

Standard Data Interface：1 × USB2.0 port

Data Functions：USB data export; one-click historical data clearance

Status Monitoring：Real-time monitoring of supply voltage, operating current, internal temperature & humidity

Real-time Display：Water depth, water level, internal temperature & humidity, voltage, current, system time and working status

Data Analysis：Auto-generate curves & charts; auto-calculate maximum, minimum and average values (statistical period adjustable)

Power-saving Function：Adjustable screen standby time, one-click wake-up

Standard Communication Interfaces：1 × RS485, 1 × RS232, 1 × 4～20mA, 1 × SDI12

Wireless Communication：Built-in 4G / NB-IoT module for data upload (optional)

Communication Protocol：MODBUS-RTU, AN-UNION

Power Supply：11 ～ 24 VDC

Storage Temperature：-20 ℃ ～ 80 ℃

Operating Temperature：-20 ℃ ～ 70 ℃

Housing Material：1.2mm high-quality steel with electrostatic spraying, coating thickness ＞ 0.1mm

Dimension (L × W × H)：190 × 198 × 58 mm

Weight：1.6 kg (excluding air pipe)