MIL-M-36954C

Military Specification - Mask, Surgical, Disposable

MIL
M
36954
C
Name: Military Specification - Mask, Surgical, Disposable
Developed by Subcommittee: N/A
Book of Standards Volume: N/A
Applicable Apparatus: The Frazier Differential Pressure Air Permeability Tester - (Breathing Resistance (delta P) Test)

Scope:

This specification covers disposable lightweight surgical masks, suitable for use by medical personnel in operation rooms and other areas where it is necessary to maintain protective asceptic techniques.

Similiar Documents:

EN 14683

Superseded Documents:

MIL-M-36954B

Index Terms:

surgical masks, surgical, disposable, pleated, pouch, molded, air exchange pressure, medical masks, R.G.I., Roger Gilmont Instrument, pressure differential, flowmeter, differential inclined draft gauge, Dwyer Differential Draft Gauge, face mask, face mask holder, mask holder, F&P Flowrator, Fischer & Porter Flowrator No. 10A1027A, pressure differential, constant air flow rate, water filled manometers, flowrator, breathing resistance, delta p

Testing Instruments: Testing Products

Additional Notes:

Breathing Resistance (Delta P)

Purpose: To determine the resistance to airflow of the facemask.

Test Method: A controlled flow of air is driven through a sample of the surgical mask containing all layers. The pressure before and after the sample is measured; the difference in pressure is divided by the surface (in cm2) of the sample.

Meaning of the value: A lower breathing resistance indicates a better comfort level for the user. It means that the mask feels cooler and easier to breathe through, and that the mask will maintain its shape in a better way as there is less pressure on the material. There will be less unfiltered air escaping around the mask.

Classification:
Type I & II (non splash resistant)=< 3,0 mmH20/cm2
Type IR & IIR (splash resistant) =< 5,0 mmH20/cm2

Comments: The breathing resistance is always measured per square centimetre of material. One way to increase comfort is to have a low breathing resistance value per cm2, the other to enlarge the surface of the facemask and thereby the total area available for ventilation.
You can compare that to a situation where you have a hot room and you want to cool it down. Your window size (breathing resistance per cm2) and the number of windows (ventilation area) will determine how fast you can cool the room down.