Looking for a very low cost data aquisition system for distance, air pressure, and temperature.

[jdunfee5]

A few days ago, I started a thread looking for a low cost distance sensor. [

http://www.eng-tips.com/viewthread.cfm?qid=357437

]

I will now expand on my original query, since I am having difficulty putting an entire system together that is affordable for us. To be specific, I need distance, air pressure, and temperature logging.

I did find a very low cost data interface, that will accept 8 10v+- signals, and comes with logging software. It was only $60, and their 4-channel version was only $30. They also come with software included.
I have not seen any other multi-channel data recording system that isn't a few orders of magnitude more expensive.

http://www.dataq.com/products/startkit/di149.htm

These sensors below are compatible wiht the above data aquisition system;
A pressure transmitter with 0-10v output for $115

http://www.automationdirect.com/adc...ainless_Steel_Sensing_Element_-_DIN_Connector

An $80 temperature controller with 0-10v output

http://www.pexsupply.com/Ranco-ETC-...-0-10V-Ouput?gclid=CIbOuqeU_7sCFSbNOgodFCIAaw

But, the linear measurement seems to be a stumbling block. I did find a very low cost dial gauge, with digital output. But it does not have the analog voltage output to work with the system I found above. Rather, it has SPC output. This seems to be a propritary serial communications system. It was only $65.

http://www.anytimesale.com/servlet/the-205/1-fdsh-2"-DIGITAL-ELECTRONIC-INDICATOR/Detail

So, the linear measurement seems to be the problem right now. I am trying to avoid making something from scratch. But, if I cannot find an affordable (i.e. under $1,000) multi-channel interface and software to record the readings, I will need to make my own using a potentiometer.

Can anyone recommend an overall low cost system with compatable linear measurements, temperature and pressure sensors?

-Joe Dunfee

 

[LiteYear]

Since the DI-149 is a tethered device, you'll have a PC or laptop in the DAQ system. Why not then plug the SPC output into it as well. That way you could have the DI-149 software alongside the SPC software both logging and do any merging manually later. A more sophisticated solution would be custom software that talks both DI-149 and SPC. Both protocols are published (eg. DI-149 and SPC).

Alternatively, there are distance transducers with analog output, but I can't recommend anyway. If you have a metallic target, maybe look at inductive sensors like the Balluff BAW002 and friends. Then there's laser sensors like the Banner L-GAGE LH. And I'm sure you've come across plenty of others of varying suitability.

 

[jdunfee5]

Thank you LiteYear for the info.

We ended up going with an inductive sensor that has an analog voltage output, and is not just an on-off sensor. The range of distance we need is just within the capabilities of the inductive sensor technology. The metal we have is not an ideal target, but my simply gluing a better metal target onto the site, it should work fine. I found it with help from a tech support guy from Omega. The price is a little more than we had hoped, but I think we will simply use fewer sensors. The important part is that I can now get all my sensors to interface with the same data acquisition device, and software.

-Joe Dunfee