- Long battery life (~1 year)
- Temperature at 5 depths logged directly to a CSV file on a uSD card
- Configurable logging rate to extend battery life or increase data frequency
- Thermal isolation between temperature sensors to reduce vertical thermal conductivity
- Guide price £80+VAT
Soil temperature governs a number of biological and physical processes, and monitoring it is a relatively simple task. The probe that we have built is 50cm long with five measurement points, but it would be relatively easy to produce longer or shorter probes with more or fewer temperature sensors using the same principles and components: please ask.
Please contact email@example.com for more information or to buy.
This simple to use temperature probe contains 5 separate sensors at 5 depths: 5cm, 15cm, 25cm, 35cm and 45cm. It is completely sealed and can be completely buried if required (although you should mark precisely where you buried it to avoid losing it!). Data is stored on a uSD card in a CSV format. The card can be popped out of the unit and the data can then be imported into a spreadsheet or other application as required. The sampling rate is set to once per 30 minutes by default, but can be changed by editting a plain text file on the uSD card. The highest rate that can be achieved is around once every 8 seconds. At the standard 30 minute sampling period a battery life of around 1 year can be expected, at 15 minute sampling rate around 6 months etc. It should be noted that the low cost nature of this device means that the sampling periods will not be precise and may drift somewhat with variations in temperature, although variations of more than 2% are unusual under normal conditions.
The probe is mounted in a 22mm OD thin-wall plastic tube and uses a removable push-fit plumbing fitting as a cap. The tube is relatively delicate and not intended to be hammered or pressed into the ground: make a hole using a corer or digging bar and drop the sensor into the hole. You can them tamp the soil down around the sensor to ensure good thermal contact with the tube. If the ground is very hard, then soaking the ground for 24 hours before attempting to make the hole can help.