Measure of soil thermal conductivity

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A5000T is a device specifically studied to measure soil heat transmission (soil tendency to transmit heat). This type of survey is usually carried out prior to install underground pipes, or prior to build geo-thermic wells to detect heat from the soil, for buildings heating or conditioning. Measurement can be done on site with the probe supplied, up to a depth of 120 cm, or in case of greater depths, it is possible to pick up samples of compact ground (logs) and perform measurement in laboratory with proper laboratory probe. Acquired data can be examined directly on site, at the end of the acquisition phase regulated automatically by the device and it is expressed graphically and numerically in watt / (metres x kelvin) where: watt = unit of power; metre = unit of distance; kelvin = unit of temperature. Operatively speaking, a hole is made into the ground using common drill (not supplied) and a perforation point of 20 mm diameter with prolonged rod (supplied). Then the probe is introduced into the hole and by pressing slightly, probe tip is fixed into the ground at about 20 cm, in order to obtain best coupling with soil. Data acquisition is initiated by pressing a button, it is managed automatically by the instrument and lasts few seconds. Numeric and graphic data is stored on SD memory and then elaborated with dedicated CTLAB software supplied together with instrument.

Heat transmission of some types of soils

- Dry loose rocks: +/- 1.5 W/m K
- Gravel, sand, water table: 1.8 2.4W/m K
- Granite: 3.4W/m K

- SPECIFICATIONS -

Heat transmission of some types of sub-soil

- Dry loose rocks: +/- 1.5 W/m K
- Gravel, sand, water table: 1.8 2.4W/m K
- Granite: 3.4W/m K

Acquisition:

- Resolution: 24 bit
- Maximum distortion: 0.0005%
- Maximum sampling: 0.3Hz
- Maximum range of inlet signal: 0-2.5V

Measurement:

- Measurement type: compliant with ASTM D 5334 and IEEE 442-1981 standard
- Measurement time: from 300s to 1020s with pitch 30s
- Calculated values: thermal λ (heat transmission) and Rt (resistivity)
- Recording support: removable SD memory up to 2 GB
- Data format: TSV, BMP

Conductivity probe:

- Specific resistance: 83 Ω/m (typical)
- Length: 350mm (in the laboratory), 1200mm (on site)
- Heater voltage: 3, 4, 4.5V set by the user
- Precision: ±0.2°C

General data:

- Watch: integrated with buffer battery
- Keyboard: 24 charge-transfer buttons
- Display: mono-chromatic graphic LCD 320 x 240 pixel
- Measures display: numeric and graphic
- Power supply: batteries AA type rechargeable and replaceable (12V - 2.5Ah).
- Typical consumption: 120mA idle, 350mA when taking measurements
- Container: anti-crash, in copolymers of polypropylene
- Operating temperature: 0-60°C
- Sizes and weight: L. 270 x H. 120 x P. 246 mm, 3 Kg