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Using a thermometer in the ground
Posted: Sun 06 Jan 2013 2:35 pm
by darc
I have just bought a prob thermometer at a car boot it measure's from
-30c up to 300c and I have checked it and it is very accurate I thought if it worked it would be useful to measure ground temp's, and it only cost me a £1, has anyone got any ideas of how best to use it, 1. I could just stick the prob in the ground 2. I thought of putting the prob in a plastic tube sealed at the top mainly to protect the prob and then place upright under the soil if I do this is there a certain depth it should be under the ground?
Re: Using a thermometer in the ground
Posted: Sun 06 Jan 2013 2:59 pm
by William Grimsley
Hi Darc,
I would just stick it in the ground because putting a plastic seal over the top could make it overread but I'm not sure on that. It's really up to choice.
Hope this helps...
Will
Re: Using a thermometer in the ground
Posted: Sun 06 Jan 2013 3:44 pm
by darc
Thanks Will that's what I have done but was not sure if there was a uniform depth it should be set at.
Thanks
Re: Using a thermometer in the ground
Posted: Sun 06 Jan 2013 3:47 pm
by William Grimsley
Hi Darc,
Sorry, I should of said, the probe needs to be about 5 cm into the ground.
Hope this helps...
Will
Re: Using a thermometer in the ground
Posted: Sun 06 Jan 2013 3:58 pm
by bruce45
Fact_sheet_No._17.pdf
Soil temperature at 0.1 m, 0.3 m and 1.0 m below the ground level
this is from the met office site might be of some use
Re: Using a thermometer in the ground
Posted: Sun 06 Jan 2013 4:05 pm
by William Grimsley
bruce45 wrote:Fact_sheet_No._17.pdf
Soil temperature at 0.1 m, 0.3 m and 1.0 m below the ground level
this is from the met office site might be of some use
Yes, that's if you're doing 3 measurements, if he is doing one he could pick any of those depths. I don't have a soil temperature probe myself so I was only hazarding a guess at 5 cm.

Re: Using a thermometer in the ground
Posted: Sun 06 Jan 2013 4:44 pm
by jdc
For what it's worth, as a farmer I find the 300mm temperature most useful with regard to crop management.
Re: Using a thermometer in the ground
Posted: Sun 06 Jan 2013 4:46 pm
by William Grimsley
jdc wrote:For what it's worth, as a farmer I find the 300mm temperature most useful with regard to crop management.
Yes! Seems the most accurate!

Re: Using a thermometer in the ground
Posted: Sun 06 Jan 2013 4:50 pm
by steve
Will Grimsley wrote:I don't have a soil temperature probe myself so I was only hazarding a guess at 5 cm.
If you don't know the answer to a question - don't guess! If you start the same tricks here that you got up to on wxforum, the same thing will happen here.
Re: Using a thermometer in the ground
Posted: Sun 06 Jan 2013 4:53 pm
by William Grimsley
Ok, lesson learnt. Sorry.

Re: Using a thermometer in the ground
Posted: Sun 06 Jan 2013 7:02 pm
by darc
Thanks for your help as I am in a farming community I will go for around 300mm if that is what as a farmer you find
helpful.
Thanks John & Steve
Re: Using a thermometer in the ground
Posted: Sun 06 Jan 2013 10:11 pm
by bruce45
I must agree with Steve
when answering posts the information must be accurate and not just guess work.
there are standards regarding recording weather information and the met office have loads of info to help us
Re: Using a thermometer in the ground
Posted: Sun 06 Jan 2013 11:15 pm
by darc
I also agree, getting the right information is important to for me as I am still very much still
Learning and the wrong information ends up sticking in my head and just causes total confusion
For me .
Geoff
Re: Using a thermometer in the ground
Posted: Mon 07 Jan 2013 7:08 am
by darc
Thanks again for your help guy's, I will have a look today at getting the temp sensor prob down to a depth of 300mm
before I do is there any protective measure's I should take to avoid damage to the cable and probe sensor before I place
it in the ground so it will really extend the life of the equipment.
Geoff
Re: Using a thermometer in the ground
Posted: Mon 07 Jan 2013 7:34 am
by bruce45
one option could be to slide it down a length of plastic conduit so the probe can be in the ground and the wire protected with the plastic. this would also indicate where it is if you have to remove it rather than having to use the wire.