With the increasing demand of sophisticated automated processing systems and the need to do precise and accurate measuring of the liquids at industrial scale has motivated the process engineers to come up with more sophisticated sensitive and accurate level measuring devices. The improvement and accuracy in the level measurement of the chemicals and other liquid products used at industrial scale has resulted in reduction in the variability of the chemical process, along with standardized and consistent product quality, reduction in the cost of production and less wastage. The new, better and latest liquid level indicator devices have enabled to achieve all these above mentioned requirements.

There are many different methods devised for measuring the liquid level which are used at industrial scale. The oldest and traditional liquid level measuring device was the sight glass. But this manual method of liquid level measurement definitely had many limitations; therefore, it is replaced by more advanced and sophisticated methods of liquid level measurement.

The latest level detection devices make use of the specific gravity for level detection. For the inference of level, hydrostatic measurements are also used. In case, the level measurements involve more complex physical principles, emerging technologies make use of computers for performing the calculation function. The data is send from the sensor in the form of readable data to the monitoring or control system where it is calculated. Some of the useful readable signals send out to the computers from the sensors include current loops, analog voltages, and digital signals. It is easy to set up analog voltages but can cause problems of annoying noise and inferences.  One of the most common mechanisms used today is the 4-20mA current loop. Current loops possess the capability of carrying the signals over quite long distances without causing much degradation in the signals. The technology of digital signals such as Foundation Fieldbus, Hart, Honeywell DE, Profibus, and RS-232, is one of the traditional and powerful mechanisms but can carry the signals only to the limited distances. The newest and latest level measuring devices make use of wireless technology which allows them to signals at vast distances without any signal disruptions.

The more advanced and modern level measuring devices are the ultrasonic level indicator, radar devices and laser. These are build up on the mechanism of level measurement which makes use of much more sophisticated digital encoding formats and uses digital computing intelligence for formatting the codes.

Today, the trend has replaced the traditional mechanical and pressure based measuring devices with the devices that measure the distance to the surface of the fluid by making use of time measurement system. The need and requirement to make precise measurements of the levels has given rise to the need of using advanced communication capabilities and digital calibration schemes in the latest level measuring devices. Now this technology is used in microprocessor based computers in almost all level measurements devices. These micro processor based computerized level measuring devices now serves the purpose of control, analysis and communication.