Level Monitoring | Ultrasonic Sensors

Real-time level monitoring over an IP network using a standard web browser!

Ultrasonic Sensors

Monitor liquid levels with an Ultrasonic Sensor and a ControlByWeb™ module (See recommended products below) Receive text messages or email alerts when a user-specified level is reached. Log and plot the level history, and more.

How do Ultrasonic Sensors Work

Ultrasonic sensors work by using ultrasonic waves to measure the distance from a target (i.e., a liquid surface). It measures distance by gauging the difference between the time the wave signal was sent, and the time the same wave was received after it bounces off of the surface.

For example, in level-monitoring, the ultrasonic sensor sends a signal which then bounces off of the liquid level’s surface. This signal then returns back to the sensor which measures the round-trip time it takes for the signal to travel. The sensor uses the measured time to calculate the distance to the surface of the liquid. The sensor reports that distance to a display and/or a controller. Using this distance, along with the tank’s dimensions and volume, you can calculate how much liquid is left in the tank that you’re monitoring. ControlByWeb modules can calculate this information for you.

The Sensor uses Ultrasonic Waves to monitor tank levels

Liquid Types

Ultrasonic Sensor works well with many clean liquids; however, it is not ideal for foamy liquids, and chemicals that produce vapors, like gasoline.

These types of liquid can cause false readings when used with ultrasonic sensors.

Clean Liquid
No foam
No Vapors

Ultrasonic Sensor Benefits

  • Easy to install.
  • Provide a reliable, non-contact method for level monitoring!

Sensor Ranges

  • We provide monitoring solutions for ranges from 4 inches to 50 feet.

Sensor Accuracy

  • Sensors are accurate within 0.25% of its detected range.


  • Monitor liquid levels
  • Real-time level monitoring both locally and remotely
  • Industrial level monitoring for mobile and static locations
  • Log level history
  • Email/text notifications for high/low levels
  • And much more…

  Compatible Products

See below for more details and to add to cart


Ultrasonic Sensors with ControlByWeb Products

Real-Time Monitoring

Each ultrasonic sensor can be connected to a compatible ControlByWeb module (see below) to remotely monitor liquid levels in real-time using a standard web browser or mobile device. Liquid levels can be presented to the user as a simple liquid height measurement, or the module can be configured to calculate the volume of liquid used or the volume remaining in the tank and present that to the user. No special software required.

Email and Text Alerts

When an ultrasonic sensor is connected to a ControlByWeb module, it can be configured to alert you via email or text whenever a certain levels are reached.

Logging and Graphing

Log and graph tank and level data. Email log files at regular intervals.

Control Options

In addition to simple remote monitoring, ControlByWeb modules are fully programmable and provide custom control capabilities as well. For example, you can connect a pump to a relay or an output on a ControlByWeb module and remotely run the pump manually, or configure module to run the pump to run automatically if the level gets too low.

Wireless, non-contact monitoring with an Ultrasonic Sensor

Ultrasonic Sensor connected to the X-420 to monitor tank levels. All products in this diagram can be purchased below.

Monitor levels remotely through our online interface, or through our App

View live tank levels with ControlByWeb’s product’s built-in interface using a standard web browser

Common Level Monitoring Industries

Ultrasonic sensors are commonly used in the following industries:

  • Medical Facilities
  • Agricultural
  • Waste Water Management

Use the RST-3002 to program the Ultrasonic Sensor

Programming the Ultrasonic Sensor using the RST-3002

Ultrasonic Sensor Setup


Connect Ultrasonic Sensor to the RST-3002 programming module, and adjust the parameters to suit your needs.


Disconnect Sensor from the RST-3002 and connect to a ControlByWeb product such as the X-418 or the X-420.


Connect the ControlByWeb product to your network. See Establishing Communications with ControlByWeb Products


Install Ultrasonic Sensor into the top of the tank.


Monitor your tank level from the internet anywhere in the world!

Compatible ControlByWeb Controllers


X-404 Modbus Master Controller




# of Sensors:Connect up to 32

Sensor Type:Modbus RS-485


  • Daisy-Chain modbus sensors
  • No voltage scaling
  • Logging
  • BASIC Interpreter
  • Email Alerts
  • Peer-to-peer


X-418 Analog Input Module




# of Sensors:Connect up to 8

Sensor Type:4-20mA


  • Scheduling
  • Logging
  • BASIC Interpreter
  • Email Alerts
  • Peer-to-Peer


X-420 Instrumentation-Grade Data Acquisition




# of Sensors:Connect up to 4

Sensor Type:4-20mA


  • Configurable Digital I/O
  • Logging
  • BASIC Interpreter
  • Email Alerts
  • Counters: Inputs 1-2
  • Peer-to-peer
EMI Softech