Abstract: A system for the measurement of temperatures in a reactor such as those operated under high pressure and/or temperature is disclosed. The temperature is measured by the use of a pyrometer which is in optical communication with a measuring duct which can be disposed in the wall of the reactor and is in optical communication with the reactor interior. The measuring duct comprises two concentric tubes the outer one of which extends beyond the inner tube in the direction of the reactor interior and has a conical construction immediately following the termination of the inner tube. The concentric tubes are provided with a common end section such as in the form of a cone in the direction of the reactor exterior. A hermetic housing defining a safety chamber is disposed exterior thereof, the hermetic housing having two opposed pressure type and heat resistant windows in alignment with the inner tube and the pyrometer. The hermetic housing is not normally permanently attached to the measuring duct.

Abstract: The volume of liquid or gaseous media contaminated with solids is measured discontinuously. To this end, an accurately measured volume of a pure medium is passed through a measuring device intended for measuring the volume of a contaminated medium. The number of the pulses produced by the passage of the pure medium through the measuring device is stored. The contaminated medium is thereupon passed through the measuring device until the number of pulses transmitted by the measuring device corresponds to the stored number of pulses. To further improve the accuracy in measurement, it is possible for the same amount of the pure medium to be passed once again through the measuring device. The number of pulses thereby produced is stored and compared with the number of pulses produced and stored on the first passage of the pure medium through the measuring device. The number of pulses last stored is modified by half the difference between the two numbers of pulses stored.