MaxBotix MB7760 SC-MaxSonar-WR Ultrasonic Sensor - 4-20mA Output, IP67

The sensor requires a 10-32VDC power supply connected across the V+ and GND terminals. The 4-20mA current loop signal is sourced from the sensor's output terminal. A precision resistor (e.g., 250Ω) is typically placed in series with the output to convert the current signal to a voltage (1-5V) for reading by a PLC analog input module or data acquisition system.

Yes, the MB7760 is well-suited for continuous liquid level monitoring in tanks. Its IP67 rating protects it from dust and temporary water immersion, and the 4-20mA output provides a stable, noise-immune signal over long distances. Ensure the mounting position avoids turbulent surfaces or foam, which can affect ultrasonic readings.

The 4-20mA current loop is highly resistant to voltage drop and electrical noise, allowing for cable runs of several hundred meters. The practical limit depends on wire gauge and loop voltage compliance of the receiving device. Using 18-22 AWG shielded twisted-pair cable is recommended for best performance in electrically noisy industrial environments.

The output is linearly proportional to distance. 4mA corresponds to the minimum reporting distance (near field), and 20mA corresponds to the maximum range (5 meters). For example, a 12mA reading would indicate an object is approximately halfway through the sensor's range. The exact scaling should be calibrated per your application using known reference distances.