Esfil Tehno AS
Esfil Tehno AS

Filtering analytical tapes NEL-3, NEL-4, LFS-2

The filtering analytical tapes represent bands of a tight uniform stratum from glued among themselves ultra thin fibrous edges of tapes, melted in a film with a width of 5 mm.

The filtering analytical tapes are intended for culling hallmarks of aerosols, including radioactive ones, with firm fragments for measuring quantity, properties and structures caught in the disperse-phase in is continuum acting instruments. Applying tapes for fabrication of analytical aerosol screens, for thin clearing of air, gases, and fluids are possible.

The filtering analytical tapes, depending on assigning, type of analysis or method of measuring the caught sediment, should be exhausted of three types: NEL-3, NEL-4, and LFS-2.

The filtering analytical tapes NEL-3 are intended for use in instruments measuring the weight concentration of dust on occluding by the captured sediment alpha or beta radiating from a standard source of radioactivity. The tape consists of a mixture of ultra thin fibres of a diameter of approximately 7 and 0.5 mkm.

The filtering analytical tapes NEL-4 are intended for use in instruments for measuring the concentrations of aerosols with the help radiometric, optical, chemical, radioactivating and other methods.

The tapes can also be applied to culling hallmarks of aerosols with the heightened weight concentration before formation of a sediment of a dust up to 2.5 mg/cm2, at stress of air below atmospheric pressure; for culling hallmarks at high, more than 170 cm/s, filtration rates. The tape consists of a mixture of ultra thin fibres with an approximate diameter of 7 and 1 mkm.

The filtering analytical tapes LFS-2 are intended for use in instruments for the separate measuring of concentrations of alpha - radioactive members and isotopes by methods spectrometry of alpha - radiating of the caught sediment. The tapes can be applied to measuring communal radioactivity of sediment. The tape consists of two strata. The upper, head-on stratum - filtering, consists of fibrous by a diameter 0.3-0.5 mkm, bottom - executing a role of a strong substrate - from the glued among them fibres with an approximate diameter of 5-7 mkm.

The filtering analytical tape can be applied in instruments at ambient temperature from -60°С up to +60°С and relative humidity up to 98%, and also at the contents of vapours of organic solvents up to 100 g/m3.

The tapes are hydrophobic, rack to strong acids and alkalis, limiting hydrocarbons, alcohols, oils, and are diluted in chlorinated hydrocarbons, ketones, and aromatic hydrocarbons.

The filtering analytical tapes allow conducting culling hallmarks of aerosols with firm fragments at the presence of fogs of oil, acids, and alkalis. An allowable weight of the caught fluid for tapes NEL-3, NEL-4 and LFS-2 - 2 mg/cm2.

The filtering analytical tapes are exhausted in a width of 50 and 25 mm. The width of the filtering portion of tapes without reinforced edges is 40 and 15 mm accordingly, permissible variation is +/-1 mm.

For specialists

The filtering analytical tapes are coiled onto a core with an inside diameter of 20-30 mm, in rolls. Length of tapes in a roll is 50-100 m.

The conformity of filtering analytical tapes to the requirements of the technical conditions for a period of 10 years from the moment of their fabrication is guaranteed in the case of the observance by the consumer of the conditions of external environments, storage and transportation established in the technical conditions.

Parameter name NEL-3 NEL-4 LFS-2
norm max deviation norm max deviation norm max deviation
Resistance to air stream at a speed of 1 cm/s, Pa 9.8 ±2.0 9.8 ±2.0 15.7 ±2.0
Penetration coefficient of an oily fog with a particle radius of 0.15-0.17 μm at a filtration rate of 170 cm/s, %, not more 15 20 10
Weight of a unit area, mg/cm2
- all stratum of a tape 1.5 ±0.2 4.0 ±0.5 3.5 ±0.5
- head-on filter bed (with a covering stratum) -- -- -- -- 0.3 ±0.1
Explosive offloading of a tape with the reinforced edges, N, not less
- width 50 mm 7.31 14.7 14.7
- width 25 mm 4.9 9.8 9.8

Appearance: A tight, uniform, not fleecy stratum of white colour, translucent, reinforced by a melted edge. The through holes and punctures extraneous firm actuation by the size more than 1 mm are not enabled.