Radiation level detectors

摘要

The free surface of a fluid (e.g. molten steel) dense to particular ionizing radiations and contained within a vessel (e.g. a casting mould) is monitored by a device which includes a radio active source positioned on one side of the vessel and a detector positioned on the side which includes a photo-multiplier having a photo cathode coupled to a phosphor scintillator of sufficient length to cover the predicted range of movement of the liquid free surface.