Reivindicaciones

1. Device for measuring the filtration efficiency of a mask (1) comprising: - a manikin (2) in the shape of a human head; - an air-impermeable enveloping surface (3) surrounding the manikin (2); - pumping means (4) connected through a first air duct (6) with a front position (22) of the manikin (2) located in correspondence with a mouth of the manikin (2), where the pumping means (4) is configured to produce an inspiration and/or expiration air stream through the first air duct (6); - a first flow sensor (5), configured to measure the flow of the inspiration and/or expiration air stream produced by the pumping means (4); - at least one first opening (10) of the enveloping surface, configured to allow the passage of air between the outside of the enveloping surface (3) and the inner space located between the enveloping surface (3) and the manikin (2); - a means for positioning a mask (1) in correspondence with the front position (22) of the manikin (2), configured to position the mask (1) in correspondence with the front position (22) of the manikin (2) without producing an airtight seal between the mask (1) and the manikin (2);characterised in that it comprises: - a second air duct (8) configured to be connected to the mask (1) in correspondence with an outer surface of the mask (1) opposite the manikin (2) by means of coupling means (9), wherein the coupling means (9) is impermeable to air and is configured to be sealed to a perimeter rim of the outer surface of the mask (1) and to an outer surface of the second air duct (8) located in correspondence with a first end of the second air duct (8), the coupling means (9) generating a cavity between the mask (1), the coupling means (9) and an air inlet located in correspondence with the first end of the second air duct (8); - a second flow sensor (7) connected to the second air duct (8) and configured to measure the flow of inspiration and/or expiration air that is filtered by the mask (1), and; - calculation means configured to calculate a filtration coefficient (Ke). 2. Device for measuring the filtration efficiency of a mask (1) according to claim 1, characterised in that it comprises a third flow sensor (11) configured to measure the flow of air flowing through the first opening (10) of the enveloping surface (3). 3. Device for measuring the filtration efficiency of a mask (1) according to claim 1 or 2, characterised in that the coupling means (9) comprises a film of air-impermeable material. 4. Device for measuring the filtration efficiency of a mask (1) according to any of the preceding claims, characterised in that the enveloping surface (3) is a surgical hood or urn. 5. Device for measuring the filtration efficiency of a mask (1) according to claim 4, characterised in that it comprises a support of the second air duct (8) on the enveloping surface (3). 6. Device for measuring the filtration efficiency of a mask (1) according to any of the preceding claims, characterised in that the pumping means (4) is adjustably configured to be able to vary the flow rate and the frequency of inspiration and expiration. 7. Device for measuring the filtration efficiency of a mask (1) according to claim 6, characterised in that the pumping means (4) can be regulated according to at least four breathing rhythms corresponding to a level of rest, a level of light physical exercise, a level of moderate physical exercise and a level of intense physical exercise. 8. Device for measuring the filtration efficiency of a mask (1) according to any of the preceding claims, characterised in that it comprises an air pressure gauge (13) located in correspondence with an orifice of the first air duct (6).