<b>Moderators note:</b> this was posted to an old thread (http://www.control.com/thread/1026233086), but is a new question deserving of its own thread.


Hi Mr. Walt,

Well I am working as a Design Engineer in a major power plant company in India. We are looking forward to change the technology being employed for Coal Bunker Level Measurement. At present, we are using Load Cell and Ultrasonic Based level sensors in the coal bunkers. Due to some problems being reported from site in the use the Load Cell, there is a proposal to change the method.

Lately, I have been reading many articles on the Net about the pros and cons of Radar vs Ultrasonic. I am not able to get a clear picture because most of the articles are biased. could anyone in this forum give me a pros and cons of both Ultrasonic and Radar.

Secondly, the frequency used by Ultrasonic based level measurement in Coal Bunkers lies within 3-10 Khz that is in the audible Frequency range and out of Ultrasonic freq. range. So I think, Ultrasonic is misnomer as far as the level measurement in the coal bunkers is concerned.

I request all the members in this forum to give their valuable inputs.

With Regrads
Tarun Garg
Engineer (PE-C&I), EOC,
NTPC Limited,
A-8A, Sector-24, Noida-201307 (UP)

 

I would seriously look at laser systems instead of either ultrasonic or radar for coal bunkers. One of the problems with ultrasonics that radar shares is dust. Coal bunkers and bins are notoriously dusty and the dust interferes with the beam transmission. Then too, there are angle of repose issues for both radar and ultrasonic. I have seen at least one vendor of laser level sensors who has a good solution to this problem. You might also look at some of the white papers here:

http://www.blueleveltechnologies.com/whitepapers.php

Walt Boyes
Editor in Chief
Control and ControlGlobal.com
555 W. Pierce Rd Suite 301
Itasca, IL 60143

wboyes [at] putman.net
www.controlglobal.com