A resistance monitor with power cut-off for automatic regulation of shadow and support film thickness in freeze-etching and related techniques.

A resistance monitor with sensors and automatic power cut-off has been developed to control the thickness of Pt-C shadow and C replica films in freeze-etching and related techniques. The monitor and sensors, in conjunction with newly modified evaporators, should considerably reduce the amount of C and Pt required and should prove useful in other applications employing vacuum evaporation of thin films of Pt, C, or other conducting materials.