Abstract: There is provided a pressure sensing apparatus that does not trap any fluid within its flow path and has a simple construction so that it can be manufactured at reduced cost and has a diaphragm that operates stably. Such a pressure sensing apparatus comprises a sensor holder 21 having a flow path 22 arranged therein and provided with a flat surface area 25 and a sensor receiving hole 23 cut from the outer periphery of the sensor holder to the flat surface area 25 of the flow path 25. The apparatus also comprises a diaphragm 24 that is level with the flat surface area 25 and has an even thickness. A pressure sensor 31 arranged in the sensor receiving hole 23. Since a pressure sensing apparatus having a configuration as described above does not have any recess that can trap fluid within the flow path 22, it does not degrade the purity and cleanliness of the fluid running therethrough, if it is connected to a piping system for fluid that requires purging.

Abstract: A water measuring system for measuring different parameters of water having a compact configuration that can be easily calibrated is provided. A plurality of individual sensors, are mounted on the housing, including a dissolved oxygen measuring sensor that can be mounted at a position separate from the other sensors. A hood member can be mounted at the lower end of the housing member to protect the sensors. A container that is capable of holding a calibration liquid can be fitted onto the housing member to provide the liquid at a position that will only contact those sensors other than the oxygen measuring sensor during a single calibration procedure.

Abstract: A measuring instrument for receiving radiation through an opening in a housing and having a protective shield member across the opening. The protective shield member is sealed against the housing to project a flexible contact portion at above ambient pressure for contacting and conforming to the surface of an object. A flexible dome on the protective shield member can pump air into the protective shield member to provide the desired internal pressure. The protective shield member is relatively thin and reaches thermal equilibrium with the object in a relatively short period of time, when the measuring instrument is a radiation thermometer.