Ultra Sonic Prox Sensors

As numerous others would ask: "More details/data please..."

The word "sensor" is pretty ambiguous, as used here. An ultrasonic (test) system generally consists of a transducer {typically piezoelectric}, and an instrument capable of sending pulses, receiving echoes and interpreting or displaying them in one form or another.

How large are the objects that are passing-by (needing counted, or 'sensed')? And how fast are they moving? How far away from the transducer will they be?

The size of the transducer ("probe") and the Pulse Repetition Rate of the instrumentation, as well as its frequency will be determined in part by this data.

Have you explored all possibilities of led/photocell combos, first? Seems like they'd be cheaper and more reliable in the long run, if feasible?

Explosion-proofing is pretty costly to establish, for a "one-off" installation.

Here's a question: has either ASTM, or any other Standards Organization written a protocol for determining the "explosion-proofness" of a newly-engineered electronic device?

"PS"~ Puser-receivers are available, with multi-channel capability, to fit PCI (PC) slots, with software available for a multitude of different applications. Only question is: How much are you willing to spend to "develop it"...?

Following this one closely ("close-to-home"!)... and Best to all ~

N e v e r _ ever reply to something when you should have been in bed an hour ago...

As I was waking, I immediately realized how 'locked-in-my-own-box' I was last night!

Certainly there are multitudes of such gizmos nowadays... all you have to do is "Search" for them! ~ I just reached under a pile of old magazines (for grins-&-giggles) and pulled-out the Sept 1993 "Electronics Now", which describes how to build your own "Ultrasonic Radar Station". Commercialization of the concept, probably even before that article, has produced quite the array of (yeah) "Sensors" of every 'flavor'.

This one would probably fit the need, though the (safety) rating isn't stated up front; surely there's a variant that would meet that criteria.

Check-out others in the "Search" link above...

Wishing you success ~

You can get some extremely accurate ultrasonic sensors both for linear measurement and for proximity sensing.

Just search globalspec...

I guess that would have been the most "politically-correct" suggestion for starters()...

[ they're about the 4th hit down, in the "Search" linked above... and, in the right-hand column of the page (at this point in time 7-11-08) is a "Harsh-Duty" series...

Best Regards ~

oops ~ now I've gone and done it (wasn't logged-in, above!)... and you don't get a chance to 'Edit' up-to 15 minutes after "Submit", when doing so as "Guest"!

~ Tom

LOL

I never log out!!

Thanks for the comments thus far, I have tried searching g-spec but nothing comes up for an intrinsically safe sensor, that is the main concern.

Hmmmm I've used them for linear sensing (forgotten the make) and they come in a nice sealed plastic package, so there must be intrinsically safe versions...

I will have a look...

John.

You need to make a chart of your operational parameters. Ultrasonic sensors and optical sensors have unique characteristics which allow them very specific applications, with a small union set where one or the other can be used. Dont worry yet about the intrinsically safe bit. Determine the required technology. Optical sensors can be made to differentiate clear vs filled, even if its water, and they can have long range with high rep rate. Ultrasonic have advantages over optical, but are challenged by range/resolution - but again these are application specific pluses or minuses.

Sick Optical makes a variety of good optical sensors, as do Banner and Balmer. I believe each make an ultrasonic sensor as well. Cambria Corporation makes a Class 1 Div 1 sensor family. Eaton has a sensor division that makes a variety of optical devices.

doug

JJ,

Look at the TC-30/30C sensors - www.microwavesensors.com . I have used them for years. Might work for your application.

Stan

Doug suggested Sick, Banner, Balmer as possible suppliers. He was right on. Turck also makes some excellent sensors. If you go to the website of Turck or Sick, You can download any information you need. You can also locate a local distributor who would be glad to come to your company and help you to determine what your needs are and give you several options. I don't know from experience, but I bet Banner and Balmer would do the same. Many such suppliers also are willing to train your maintenance techs in-house on proper adjustments, troubleshooting, etc. of their products.

http://www.turck.com/

http://www.bannerengineering.com/en-US/

http://www.sick.com/home/en.html

Best of luck

Ping))) Sensor Circuit from Parallax www.parallax.com/

/Ari (Orphuese)