Solid State Electronic Densitometer.

Solid state elements are today widely used in instrumentation Densitometers are now available based on these devices. This paper discusses their inherent advantages such as battery operation, elimination of warm-up time, shock-proofness, longer operating life and digital display. It also points out the limits of transistorization. It is shown that the only element which cannot at present be replaced by solid state devices is the photo-multiplier. This is due to the extremely low light levels which modern densitometry has to cope with. Finally, a brief technical review is given of a line of solid state densitometers which have been known in Europe for some years and are now being introduced to the American market.