Where can I buy a soil temperature device?
93071
www.aquaticecosystems.com
337103
Temperature measurement
1015051
there are these surveyor guys who examine soil to evaluate its potential for residential or commercial building. I'm not sure where to find them though...you might want to google or call a local contractor in your yellow pages.
1029257
I found one here for about 750$ :\n\nhttp://gps-applications.com/WanderCare100T.htm\n\nAnother one is sold here, but no price given:\nhttp://www.stopllc.com\n\nGood luck!
122834
You should choose something you could actually finish, so keep it simple.  One project that you could finish and possibly sell copies to friends and family: a digital thermometer and relative humidity sensor.  Everyone wants to know the temperature.  The problem with the relative humidity sensor is that the sensor is not linear from 0-100%RH, so there is error.  Using a PIC microcontroller you can write a software correction program that will correct the sensor output (the thermometer can have the same problem).  Depending on how much math background you may have, this could be an easy or difficult project.  The upside is that you may be able to commercialize the product.  We've done projects with silicon pressure diaphragms correcting for pressure and temperature error (requires a matrix solution leading to polynomial coefficients and a lookup table) - it took years however, so keep the project simple.
374951
http://www.mytempdir.com/500748 \n\ntry this! ive tried it b4, works fine!
790182
You can try Froogle...Amazon.com, or search Google for your needs!
32890
Go to either Lowes or the home depot web pages.You should find something there.
707592
Check Radio Shack, they have all that stuff.
1092375
You can find them in the telstra stadium bins on the 12th\n\nFind ur local tiketek Dealer
196298
a thermometer for temperature, but for tenperature i don't know.
431405
I am not sure where to find a supplier, but maybe ebay has some?
25140
Oregon Scientific makes a good one:\nhttp://www.ambientweather.com/wmorscwiprwe.html\n\nYou can look at some alternates there too.
267140
From Stewart-MacDonald\nwww.stewmac.com\nhttp://www.stewmac.com/shop/Electronics,_pickups/Potentiometers_and_push-pull_pots/2/Potentiometers_and_Push-Pull_Pots.html
834757
You can get it from Sigma-Aldrich.\nCheck their website for a provider / agent near your location. And probably you will not get it if you are going to use it for some private use.
25444
You could try to make an accurate experimental thermometer by glueing two strips of dissimilar metals together along their lengths. Perhaps try copper and steel or copper and aluminum or steel and aluminum.  Try perhaps one half inch wide by six inch long strips.  Use sheets of metal that are equally thin.  Perhaps cut the strips from aluminum soda cans and steel soup cans, etc.  Use a magnet to check for steel vs aluminum.  Glue the strips together using epoxy or super glue.  Attach one end of the combined strip to a firm base and leave one end free to move in front of a paper scale.  You now have a bimetalic thermometer.  The thermometer can be made to be more sensitive by using greater length strips and bending the strips into a spiral and attaching a pointer to the free end of the spiral to amplify movement.  This is how most oven thermometers are built except the metals are joined without glue.  The principal of operation of a bimetalic thermometer is that one  metal expands or contracts more or less than another metal.  When joined, a temperature change causes the combined strip to bend.  You can calibrate your thermometer by marking its "pointer" position at two or more large temperature changes then calculating the total deflection divided by the total temperature difference to get deflection per degree (either F or C).  Be careful with tin snips and epoxy or super glue.  Good luck.\n\nAs an alternative, you can make a highly accurate experimental thermometer by winding very thin insulated copper wire (like that used in toy motors) around a wooden spool and connecting the scraped   wire ends to an accurate ohmmeter to measure resistance change vs temperature change.  Calibrate as before but remember that calibration temperatures must be steady long enough for any lag to catch up.  This is called a resitance thermometer and accuracy will depend on the length and thinness of wire and sensitivity of your ohmmeter.  Also the ohmmeter should not cause enough current to flow in the wire to heat the wire.  Observe for drift (increase in resistance and temperature) while taking measurements.
263867
try the lowes website