Abstract: A pressure sensor is provided. The pressure sensor includes a sensing element, a case, a line element, an insect entering restriction element. The case has a space for receiving the sensing element. The case includes a pressure introduction passage, which is in communication with the space to introduce a pressure medium into the sensing element. The line element has a first portion electrically connected with the sensing element and a second portion to be electrically connected to an external element. The insect entering restriction element extends across a path on the exterior surface of the case, the path interconnecting between the second portion of the line element and the open end of pressure introduction passage.

Abstract: An adding flowmeter comprises a liquid chamber and is divided into two chamber parts by a membrane fixed to a slide which is able to move along a rod. The rod controls a slide valve for the supply and discharge of liquid to and from each of the chamber parts. By means of two abutments against which the slide bears on the rod, the membrane is able to move this rod in order to reverse the supply and discharge connections of the flowmeter so that the membrane carries out a reciprocating movement, filling one of the half-chambers and emptying the other, then vice versa. The number of changes of state of the slide valve are counted to determine the volume of liquid which has circulated in the flowmeter.