Rotary Position Sensor

bon,

using the same method you used to find this site, you might have tried a search first:

Rotary Position Sensors - Honeywell Sensing and Control

Hi bon,

Try sick.com they make a range of "safety laser scanners" that could be what you are looking for. Multiple units can be fitted to your crane to give all round sensing.

Hope this is of help.

Best of luck with your project,

John

First, are you trying to measure the rotational position of a shaft? If so, what degree of reliability do you need?

That answer will point you into one or two directions.

There are linear Hall sensors that provide 360° rotational measurement and they are reasonably robust

Sentron makes such a Hall sensor chip. See this link for more information.

The downside is that you will need to integrate this device into some form of package and you need a microprocessor to decode the data.

The advantage is a very high resolution and good repeatability.

The best solution for highest accuracy and robustness is called a "resolver".

You can learn more about resolvers at this link.

A third solution that has a very high resolution and is very robust is called LVDT. In your case you are interested in something called RVDT. You can learn more at this link.

If you are looking for proximity sensing in a 360° direction, that is a whole other bag of worms and you have not provided nearly enough requirements to even begin that discussion in a useful way.

there are many kinds of rotary sensors available

some are even suitable for submerged operations

see pe seatools website for systems details and ideas

Try sunx sensors.Those works fine.Perhaps there is a special model for you or pehaps you need install severals...

Thank you very much for all your replies and suggestions. I appreciate it very much.

I have considered before rotary sensors, hall effects, contactless rotary sensors, potentiometers but i have a big problem. Crawler Cranes are factory manufactured. I can`t see nor have any access on the rotating part of it. Thus i can`t think how to attach the above sensors. Also, there are a lot of types of crawler crane from different makers and most likely the rotating part is not all the same.

I am looking for something like i will place anywhere outside the crane that will give me a 0-360 degress data. Finding one like this will be applicable to any type of crane.

I am thinking of magnetic compass but i know these are inconsistent to metallic distortion. Yesterday I found a magnetic compass saying it has "integrated perfect auto calibration". I am not sure if this is true.

Thanks to John too about the sink.com...Their sales representative will visit our office today.

Thanks a lot.