Common Types of Tank Level Monitoring Systems

Remote tank level monitoring has many different applications in the industrial space. From frac tanks to water tanks, this innovative technology is the future of tank monitoring and gives you valuable insights into what is going on inside of your vessels and tanks.

Importance of Tank Level Monitoring

The goal of tank level monitoring is to keep track of the volume of liquid in a tank. In addition to the level of liquid within the tank, monitoring systems measure other important statistics about the contents in a vessel. They can measure temperature, pressure, and volume, giving you valuable insights into your tanks.

Tank monitoring systems can greatly improve your business operations by allowing you to optimize tank operations, reduce company costs, increase safety and security of your tanks, and can increase efficiency. They can also help to prevent and eliminate spills of valuable product.

The 5 Types of Level Monitoring Sensors

The five most common tank level monitoring sensors are capacitive sensors, float sensors, hydrostatic sensors, radar sensors, and ultrasonic sensors. Continue reading below to find out more about how these sensors and the best applications for each sensor type.

1.     Capacitive sensors

Capacitive sensors are one of the most versatile tank level sensors. They use two conductive probes (electrodes) that extend into the tank. They then measure fluid in the tank by reading the changes in electric charges (capacitance) as the level in the tank changes. This sensor type can even be used to measure solids.

They are in the middle ground in terms of cost. In addition, they can be very sensitive to environmental condition changes. In fact, things like humidity and temperature can affect the accuracy of the readings. They also require some maintenance and can be harder to operate than other sensor types. Capacitive sensors require calibration when a tank to both empty and full.

2.     Float sensors

A float sensor is another common type of tank level monitoring sensor that uses a probe that extends all the way to the bottom of the tank. The sensor has floats that will activate the sensing elements located along the probe.

Float sensors give extremely accurate, reliable data and do not have problems with interference from noise. In addition, that can measure fluid interfaces (when more than one fluid type of in the vessel) by using floats for different liquid densities.

Predicting the cost of installing a float sensor can be difficult but are typically pretty expensive. The price of these sensors will increase as the height of the container increases.

The other problem with float sensors is that they require regular cleaning or more expensive materials such as oleophobic probes in order to get accurate readings. For some liquids that can be gummy or waxy, static interference may occur if the floats stick to the probe.

3.     Hydrostatic sensors

Hydrostatic sensors are one of the most cost-efficient ways to get accurate data on the levels in your tank. These sensors are flexible in use, inexpensive, and use very little power to run. They use hydrostatic pressure of the fluid above them to monitoring the inside of a tank.

This type of sensor needs placed at the bottom of a tank and should completely submerged. They can also be mounted to the discharge piping at the bottom of the tank.

However, these sensors should not be used in corrosive or caustic liquids, as this can cause them to fail. Corrosive liquids will damage the sensor and can work themselves into the cable gland and cause it to short circuit.

4.     Radar sensors

Radar sensors use sound to measure the volume of liquid in a vessel using radio waves. It bounces radio waves off of the fluid surface and measures the tank level by how long it takes the radio waves to travel back to the sensor. It is important to note that radar sensors different from ultrasonic sensors because they do not use sound to measure tank levels.

This sensor type is non-contact and installed above the liquid in the tank. They are the most accurate type of non-contact sensor and are not susceptible to interference. Some of these sensors can even measure fluid mixture. For example, oil and water.

However, radar sensors are extremely expensive. A good radar sensor can cost a few thousand dollars. Like other types of non-contact sensors, they need a blanking zone in order to accurately measure the tank level. The other downside to radar tank level monitoring systems are that they are not accurate when a tank is being filled, as light waves travel much faster than sound.

5.     Ultrasonic sensors

The last sensor type we are going to go over are ultrasonic tank level sensors and are similar to radar sensors. Ultrasonic sensors use sound waves to measure the level of the liquid in the tank. They sit at the top of the tank and use ultrasonic waves to bounce off the surface. The tank then measures the level based on how much time it takes for the sensor to register the echo.

These sensors do not touch the liquid in the tank. With ultrasonic sensors, you do not have to worry about the compatibility of the fluid with the sensor because the sensor never comes into contact with the liquid.

Ultrasonic tank level sensors work very well in tanks with moving components within the liquid, such as mixers. But, these parts must be turned off to get an accurate level reading. These sensor systems are reasonably priced but may be more expensive if you are monitoring hazardous materials.

The downside to this sensor type of that they take a lot of power to run and cannot be run off batteries. They also require a lot more maintenance than many other sensor types. Ultrasonic sensors must be installed with great precisions and maintain a blanking zone, which is a set distance between the sensor and the fluid in the tank. The last downside this sensor type is that they can be susceptible to noise interference.