Bonner Q45U Ultrasonic Sensor in Practical Use

Application Cases and Selection Suggestions

9.1 Liquid level monitoring (water tank)

Requirement: Measure the water level at 0.3-1.2 meters and output 4-20mA to the PLC. The sensor is installed at the top of the water tank, with a distance of 1.2 meters when the tank is empty and 0.3 meters when it is full.

settings

Output type: Current (DIP2=ON).

Slope: Proportional (DIP1=ON), as the water level rises (distance decreases), the output should decrease, but usually PLCs expect high liquid levels to correspond to high currents. Adjustable logic or use inverse ratio.

In fact, if you want a high liquid level of 20mA, then a low liquid level (close range) corresponds to 20mA, so it should be set in inverse proportion (DIP1=OFF): the closer the distance (high liquid level), the greater the output.

Window: Near limit (full tank) 0.3m, far limit (empty tank) 1.2m. Place the target object separately during TEACH.

Echo loss: Set to minimum maximum value, default output maximum value (20mA) indicates fault (DIP3=ON, DIP4=ON).

Response speed: Position 4 or 5 (640ms or 1.28s), smooth liquid level fluctuations.

9.2 Detection of blockage at the discharge port

Requirement: Check if there is material accumulation at the funnel outlet (distance<500mm). Output within the range of 0~10V, output ≈ 10V when there is no material, output ≈ 0V when blocked (or vice versa).

settings

Voltage output (DIP2=OFF).

Proportional slope (DIP1=ON): The closer the distance (with material), the smaller the output.

Window: Near limit 100mm (closest to sensor), far limit 500mm (normal no-load distance). Set the far limit to the distance when there is no material and the near limit to the distance when there is blockage. Actual materials should be placed during TEACH.

Response speed: Position 2 (160ms), fast response.

Echo loss: Keep mode (DIP3=OFF) to avoid false alarms caused by brief loss of echo.

Maintenance and lifespan

Q45U is a solid-state sensor with no moving parts and a long theoretical lifespan. However, it should be noted that:

Regularly clean the transducer surface to avoid dirt and ice cover, otherwise the ultrasonic signal will be attenuated.

Check if the cable is damaged and if the quick disconnect joint is sealed (O-ring is not aging).

If in a reinforced corrosive environment (such as acid mist), PBT material may discolor, but its performance is not affected in the short term. It is recommended to use stainless steel brackets.

Alarm light indicator: Green flashing indicates an open circuit in the current circuit, and the wiring should be checked.