As part of a frost protection scheme on a fruit farm I need to deploy a number (approx 6) of temperature sensors around the farm, the max distance from reciever to transmitter will be approx 700m, Line of site is not always possible. I will have a PC monitoring the sensors and taking the necessary action when the temperature drops. Does anybody have some suggestions on how I might best achieve wireless communication between a thermocouple and my PC?

Thanks

Stuart

 

Hi Stuart,
Is it really a must to go wireless ?
There are several ways to do this with a simple 2-wire system, either analoque or digital.
Best regards, Henk.
you may contact me at : [email protected]

 

Depending where you are in the world, Europe, USA, etc I know Omni Instruments (http://www.omniinstruments.co.uk) have a number of different wireless solutions.

Richard

 

Hi Stuart,
Since I have little experience with software development, I was planning to design a simple hardware solution for a frost protection system on a fruit farm. I will probably use my earlier designed 4-20mA t/i converter, wich is powered by the two communication wires, at the other end I have this receiver, wich not only converts the current into a suitable voltage, but also feeds the just mentioned transmitter.
I have already tested this system for a distance of 4KM, no problem at all !
Now here is my problem; I need software to control this system by a PC monitoring the sensors and taking the necessary action when the temperature drops.
Is there some way, that I can make use of your software ? If you would go for a hardwired solution, we could exchange now how.
Your answer would be very much awaited.
You can reach me at : [email protected]
Let's share our experiences.
Best regards, Farmer.

 

Hello Stuart,

My company is developing a line of wireless sensor interface devices and we feel we can help with your project.

A hybrid of custom and off-the-shelf approaches assures that you get a solution that matches your needs, yet does not cost as much as full custom work.

Please contact me off-list if you are interested.

Sincerely, Michael Shiloh [email protected] MakingThings www.makingthings.com

 

I am VERY interested in getting info/pricing on whatever systems you have for LONG range wireless temperature measurement. I work for a systems integrator and one of my projects is to install a wireless temp monitor system into a 4 story apartment building. The systems I can find out there are a little pricey, and somewhat limited.

 

Stuart, I found this site.
http://www.inovonics.com/wirelessTemperature/temperatureProducts.jsp

 

There are plenty of cheap or rather inexpensive 802.11 wireless sensor solutions available on the market to day. 1) they do not require a 900Mhz $125 antenna, 2) no mast 3) no grounding and 4) are easy to program and configure.

Also, a wired solution is not bad, you can get direct burial cable, put it in a trench 18" deep, and use a TC to current loop convertor (or even RTD) which is loop powered, this way no batteries at the remote points sand can be housed in a small 4" enclosure. I would start checknig prices of parts and such at www.digikey.com or www.newark.com

Not to rain on anyone's parade, but the innovonics stuff is pretty pricey and is not very rugged - used some here in Colrado and had to replace all of it after a year in the field - not impressed.

I would check out www.sensorsmag.com

great resource site, links to various wireless sensor manufactures and products.

MJH