Maker's Name: 
Beckman Instruments, Inc.
Where made: 
59 × 36 × 25 cm

Metallic housing, with sample placement door at front. Front panel controls for photomultiplier offset and calibration and wavelength selection. Relative absorption read from a meter at front, or may be connected to a chart recorder. 220V, 1A, 50Hz power supply. Ports at the rear allow the circulation of coolant through sample chamber.

Light from either a tungsten lamp (visible) or a hydrogen lamp (UV) is split into two beams. A grating is used to isolate a particular wavelength for study. One beam passes through the sample being analysed and the other is a reference, and the beams are detected by a photomultiplier. A signal is then produced which indicates the relative absorption of that wavelength by the sample. The grating may be set to scan across the available wavelengths at a constant rate and the results recorded by a chart recorder (not present). A coolant circulation system was an optional feature which has been installed on the device (probably added subsequent to purchase).

The primary uses of such a spectrophotometer were biological assays, analysis of biological samples and the study of the rates of production of reaction products in the life sciences. The device on display was in use by the Biochemistry Department at The University of Queensland until 1991 and was certified as serviceable by that department 03/04/90. It appears undamaged and in fair operational order.