Weston Light Meter Model 614. 1942, USA manufacture. This model of industrial light meter measuring foot candles was in production with Weston continuously from the '30's to the '50's. The early Model 614 appears identical. However, the Cell is fully exposed in that model The later Model 614 here has an incident light diffuser fitted.
After Weston, Huygen took over some production (reputedly) and servicing / upgrading of this model.
A rheostat selects from three ranges for the incident cell: to 100, 250 and 500 foot candles. An incident cone is mounted over the cell (on this model) which hinges upwards to direct to the light. Stood on a flat surface using the box lid for support, the unit can be angled towards any light source.
Full instructions for use and recommendations for levels in different work environments are printed on a panel attached to the inside hinged cover.
This model above is later than the '30's. Earlier models have no diffuser mounted over the cell which is therefore directly visible. The range switch type is also more basic (see below).
Cell and switch detail of early model Weston 614. There is no incident diffuser over the cell and a more basic range switch is fitted.