FIELD: measuring instruments. SUBSTANCE: pickup generates a signal proportional to a pressure difference between the pressure in the pipe line and atmospheric pressure. Space 44 for sensor and spaces 12 and 13, wherein ignition can occur, are in communication with the atmosphere through flame arresting ducts. Opening 22 in the housing of pickup 10, wherein sensor 45 is mounted, has a plug which is provided with space 44 for the sensor and holds sensor 45, and fitting 26 which is connected with the delivery pipe line. Insulator 35 is used for transmitting working pressure to sensor 45 through insulating diaphragm which acts on an incompressible material filling space 44 of the sensor and transmitting the pressure through path 35B. The path is shaped so that to provide flame arresting. Path 35B insulates sensor 45 from pipe line with fluid. The opposite side of sensor 45 is connected with the atmosphere through paths which arrest flame owing to its shape. Plug 35 can be made up as an easily mountable and dismountable unit which provides safety almost if some of the members, such as insulating diaphragm 35A or welds between the parts of plug 35, are damaged. EFFECT: enhanced safety. 8 cl, 3 dwg
