Different Types of Level Sensors and their Workings

Liquid level sensors have been available in markets around for decades like food and drink, manufacturing, therapeutic and household, printing, and agriculture, automotive and white goods for leak recognition or level capacity. Some tool manufacturers may also be amazed at both the variety and intellect of level sensing choices available on the market. Developments that used to occupy expensive pieces of apparatus can now be attained using original, innovative and clever technologies that can be expensive, dependable, strong, highly precise and easy to install. Liquids that have historically been known to be enormously challenging to sense like soap containing bubbles or foam, milk, and sticky materials such as ink and glue are now showing possible and easier to notice with the different types of level sensors available. This article will explain the most general kinds of level sensors obtainable on the market today.

Types of Level Sensors and Its Applications

A level sensor is one kind of device used to determine the liquid level that flows in an open system or closed system. The level measurements can be available in two type’s namely continuous measurements and point level measurements. The continuous level sensor is used to measure the levels to a precise limit, but they give correct results. Whereas point level sensors used to determine the level of liquid whether that is high or low.

Types of Level Sensors
Level Sensors

Generally, these sensors are connected to an output unit for sending out the results to a monitoring system. The present technologies use wireless transmission of information to the monitoring system, which is very useful in important and hazardous locations that cannot be simply accessed by common workers.

Classification of Level Sensors

The major types of level sensors include the following

Ultrasonic Level Sensors

Ultrasonic level sensors are used to detect the levels of sticky liquid substances and bulkiness materials as well. They are worked by producing audio waves at the range of frequency from 20 to 200 kHz. These waves are then replicated back to a transducer. The ultrasonic sensor’s response is influenced by turbulence, pressure, moisture, and temperature. In addition, the transducer is necessary to be increased appropriately to obtain a better response.

Ultrasonic Level Sensors
Ultrasonic Level Sensors

Pros and Cons

  • Compact, cost-effective
  • Invasive, numbers of users are limited

Applications

The ultrasonic level sensors are used to control the liquid level, fine-grained solids within mining and powders, food and beverage industries and chemical processing.

Capacitance Level Sensors

These sensors are used to detect the liquid levels like slurries and aqueous liquids. They are operated by using a probe for checking level changes. These level changes are transformed into analog signals. The probes are generally made of conducting wire by PTFE insulation. But, stainless steel probes are extremely responsive and hence they are appropriate for measuring non-conductive substance granular or materials with low dielectric constant. These types of sensors are very simple to use and clean as they do not have any moving components.

Capacitance Level Sensors
Capacitance Level Sensors

Pros and Cons

  • Solid-state, compact, can be non-invasive, accurate
  • Can only be used in certain liquids, May require calibration

Applications

They are commonly used in applications like Tank level monitoring in chemical, water treatment, food, battery industries and involving high pressure and temperature.

Optical Level Sensors

Optical level sensors are used to detect liquids including poised materials, interface between two immiscible liquids and the occurrence of sediments. They are worked based on the changes of transmission in infrared light emitted from an IR LED. The interference from the produced light can be reduced by using a high energy IR diode and pulse modulation methods.

Optical Level Sensors
Optical Level Sensors

Continuous optical level sensors, on the other hand, use the highly intense laser light that can infuse dusty environments and notice liquid substances.

Pros and Cons

  • Compact, high pressure, no moving parts, and capability of temperature, can notice tiny amounts of liquids.
  • Invasive as the sensor needs get in touch with the liquid needs power, certain wide substances can reason coating on the
    Prism.

Applications

They are commonly used in applications like leak detection and tank level measurement

Microwave Optical Sensors

These types of sensors are used for applications like varying temperature, pressure, dirty and moist environments, as microwaves can easily go through under these situations without involving air molecules for energy transmission. Microwave Optical sensors can notice conductive water & metallic substances. The measurements are accepted using time domain or pulse reflectometry.

Microwave Optical Sensors
Microwave Optical Sensors

Pros and Cons

  • No calibration required, very accurate, multiple output options
  • Costly, limited detection range, and can be affected by the environment.

Applications

They are commonly used in applications like vaporous, Moist, and dusty environments. They are also used in systems in which temperatures differ.

From the above information, finally we can conclude that types of level sensors can be used in various applications like high-level sensing or low-level sensing, alarms, overfill shutoff, leak detection, and also they are found in a wide variety of industries like marine, manufacturing, chemical, food and beverage, pharmaceutical, medical, and fuel/energy management.Furthermore any queries or to implement sensor-based projects please give your feedback by commenting in the comment section below.



2 Comments

  1. Deviprasad a says:

    May I know which sensor can be used to check the fat,water content, sugar level, temperature and defecting chemical content in milk.

    1. Tarun Agarwal says:

      Hi Deviprasad

      The smartphone-based sensor is used to detect milk adulteration.

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