Radon detector RM-2
Equipment for in-situ permeability
More information you can find at http://www.radon.eu
Equipment for in-situ permeability measurements RADON-JOK|
Equipment for in-situ permeability measurements RADON-JOK is a portable equipment, which has been developed for in situ measurements of gas permeability of soils ("radon permeability"). Its robustness and its simplicity is very practical for easy, quick and at the same time sufficiently exact in situ investigation.
The principle of the RADON-JOK equipment is based on air withdrawal by means of negative pressure. The air is pumped from the soil under constant pressure through a specially designed probe with a constant surface of contact between the probe head and the soil. The constant active area is created in the head of the probe (driven into the soil to a measured depth) by the extrusion of the tip by means of the punch wire inside the probe by an exact distance. The special rubber sack, with one or two weights, pumps the air from the soil and allows to perform measurements at very low pressures. The "radon permeability" is calculated from the equation using the known air flow through the probe. The air flow is defined by the known air volume (= 2000 ccm) in the rubber sack (depression of the bottom of the sack between two notches) and by the pumping time measured. The great advantage of RADON-JOK is the possibility to perform measurements independently of any source of energy (electricity, compressed air..).
Theoretical framework for the permeability measurement is based on Darcy's equation /Koorevaar et al. 1983/.
Using the RADON-JOK system, with the shape factor F = 0,149 m, the feasible range of measured "radon permeabilities" is approx. from E-11 to E-14 m2. The maximum detection limit (- measured time about 8 s - E-11) is determined by the resistance of the equipment, the minimum detection limit depends on the time spent by any given measurement ( we use near 1E-14 ).
The RADON-JOK equipment including basic accessories
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