Abstract: The specification discloses an apparatus for assessing the ingress of air into a steam system which includes a steam condenser having an exit, a vacuum pump arrangement for maintaining the exit under a partial vacuum, and pipework connecting the exit to the vacuum pump arrangement. A pitot probe is positioned at a first monitoring point in the pipework to sense the total dynamic and static pressure of the entire flow in that pipework. A second probe is positioned at a second monitoring point which is displaced from the first monitoring point and adjacent the exit from the condenser, to sense the static pressure and temperature at that second monitoring point. An indication of the amount of air flowing past said first monitoring point is derived from the total pressure, the static pressure and the temperature, which are measured at the first and second monitoring points.

Abstract: Apparatus for providing a calibrated gas pressure comprising a piston mounted within a cylinder, there being provided a gap between adjacent walls of the piston and cylinder, the cylinder being generally closed at one end so as to provide a closed chamber. The closed chamber includes an outlet for gas at a calibrated pressure and a variable outlet valve. A gas inlet is provided in the wall of the cylinder adjacent to the position of the piston, and the piston engages a force measuring apparatus such that gas, in use, is supplied to the gas inlet and passes to the chamber to provide a calibrated gas pressure within the chamber, the pressure being measured by the force measuring apparatus.