Practical measuring appliance for determining temperature profiles in solid structures

Ever dreamed of a simple solution, measuring and displaying temperature profiles in solids like:

• walls of buildings
• soil
• heaps heating up from anaerob processes
• drying matter like straw

The printed circuit board PCB based probe is impregnated to withstand humid environment. It is quickly inserted and comes with pre-localized sensors via XML, so the temperature gradient may be calculated quickly.

Question : So if you have only one borehole, how significant are the measured values for the actual position?

Answer : The printed circuit has lower heat conduction than brick or concrete walls, and the PCB cross-sectional area is only 6mm x 2mm=12mm of the total 28m². The cavities are covered via insulating strip, so longitudinal air circulation is strongly reduced. The sensors are also in direct radiative contact to the wall, since there is no surrounding hull, which might induce heat flow from other layers.

Question:How many measurements are possible per period of time?

Answer : The conversion of the temperature needs 100ns to 750ms 9 bit/12 bit, according to the specification. Those conversions however are made in parallel in the digital sensors. Typical construction structures have quite high heat inertia, so this is absolutely no limitation.

Question:What is the heat release of the digital sensor?

Answer : The input current of one DS18B20 is only 5µA, so there is very low heat dissipation.

Question : Is the reading of the 1-wire bus data complicated?

Answer:Raspberry Pi's have embedded support for 1-wire. You may also employ USB-connected converters, so all platforms are supported.

What accuracy is to be expected: The main difference to resistive temperature sensors is that the digital sensor is embedded in a polymer with a conductivity of 383 W/mK. The drift is +/- 0.2 K per 1000 hrs. No errors are induced after digitalization in the DS18B20 temperature sensor.

Data upload may be done via Python on a Raspberry Pi zero or even less powerful boards, however HTTPs shall be usable. No additional cost is resulting from the use of the visualization solution if you opt for storing data on our server opting for an all-in solution. To store larger quantities of sensor data, your own data server or a separate installation (database table) shall be set up. Please ask for an offer at office@effiziente.st.