| 摘要 |
1,136,641. Testing the leak tightness of respiratory masks. COMMISSARIAT A L'ENERGBE ATOMIQUE. 13 Jan., 1966 [21 Jan., 1965], No. 1708/66. Heading A5T. Apparatus for testing the leak tightness of respiratory masks comprises an inflating system 1a including at least one inflatable head 6, 7 over which the facepiece to be tested is placed, said head being inflatable by pump means 2, deflating means 4, and a manometer 10 disposed in said inflating system at the end which is remote from said pump means, and a system 1b for producing a partial vacuum in the facepiece comprising a suction pump 11, valve means 12 to regulate the degree of vacuum produced beneath said facepiece, flowmeters 14, 15 for measuring the evacuation rate from said face piece, and manometer means 18 disposed in said partial vacuum system at the end remote from said suction pump 11 and protected by fluid traps 19, 20. The maximum volume of each inflatable head is limited by a microswitch 8, 9 controlling the inflating pump 11. In use a face mask is placed over an inflatable head, the interior of the face mask is connected, to the suction pump 11 and the manometer 18 through changeover valves 16, 17 and a needle valve 12 is adjusted to give a partial vacuum in the face mask corresponding to that reached on inhalation during use of the mask. The rate of evacuation of the face mask measured on the flowmeters 14, 15 while this partial vacuum is maintained in the face mask is equal to the rate at which air leaks into the face mask during inhalation. |
