-
Soil Moisture Sensor Update
Apr 16My Watermark soil moisture sensor and additional circuit has been running 24/7 for about 4 months now, and it really is a stable system. Here are the data collected so far:


On the week graph you will notice an oscillation peaking high at 6 PM and low at 10 AM every day:

Compare the above graph to the weekly temperature graph and you will see the connection to the soil temperature:

When the soil temperature goes up, so does the soil moisture reading. It could be that the accuracy of the soil moisture measurement is highly temperature dependent. Another explanation could be, that air is able to contain more moisture at higher temperatures and this more humid air somehow spreads to the soil and raises the soil moisture level.
What do you think is the explanation? Please leave a comment.
If you enjoyed this post, make sure you subscribe to my RSS feed!
Related posts:
One Response to “Soil Moisture Sensor Update”
-
Michael said on May 7th, 2009 at 3:03 pm
Inspired by your site I got the same devices.
If you find anything further about the relation of soil-temperature and current readings I’d be very interesed..I found something very interesting here:
http://www.emesystems.com/pdfs/SMX.pdfI guess measuring the soil temperature (also while calibrating) and using it for compensation should be possible..
Keep up the good work!
Michael
Leave a Reply
-
Subscribe in RSS reader
Subscribe to email newsletter
About
-
Are you ready to grow your own food? Take a tour through my archives and learn how I did it!

Recent Articles
Popular Articles
- How To Install Debian On NSLU2
- Building A Better Bean Trellis
- How To Build A Bumble Bee Nest
- Choosing The Right Type Of Composting Box
- Soil Moisture Sensor Circuit Explained
- How To Prune Black Currant
- Pruning Red Currants
- 31 Things You Need To Know About Peaches Before You Start Digging
- Still No Peach Leaf Curl
- Peach Tree

