Friday, January 5, 2018

Radar Level Transmitter Application

non-contact radar level transmitter in process tank
Radar level transmitters can be configured for non-contact
measurement of liquid levels.
Image courtesy Nivelco Process Control Co.
Radar is generally accepted to encompass means by which electromagnetic waves of short wavelength (microwaves) are used to detect the presence of, and distance to, a remotely located object. While the technology is probably best known for its use in miltary and air traffic control scenarios, radar ranging technology has also been put to industrial processing use in measuring the level of liquids and solids in containers of many types.

Very simply, a radar level measurement instrument emits a burst of electromagnetic energy and measures the time interval from its emission to return. The emitter directs the microwaves toward the surface of the material to be measured. As the distance from the emitter to the material increases, so does the transit time of the wave on its round trip from emitter to media surface and back to a detector antenna. This transit time is proportional to the distance from the emitter to the media surface and can be used to calculate the media level.

Radar level transmitters can provide onboard processing of the raw signal, delivering a standard industrial process control signal which is scaled to a useful value range indicating percentage of tank fill, or some other useful representation of media level.

Radar level technology is utilized in a guided wave format, where the emitted energy travels down a tube extending into the medium, and non-contact configurations with the microwave emissions dispersing as they travel from the source antenna. Both types deliver excellent accuracy and have their specific application criteria where they may be preferred.

Properly selecting and applying level measurement instrumentation requires consideration of many operational and technological aspects of each process. Share your process measurement challenges with application specialists and leverage your own knowledge and experience with their product application expertise.