Metal auriscope, head section only, Europe, 1900-1930 Early 20th century metal head of auriscope 1900-1930
Thermalert Infrared Thermometer System, model LC814LBC, serial no. 5960, range 40-200° C, made by Raytek Inc. Santa Cruz, California, USA. (Sensing head incorporating pyroelectric sensor and signal processing system only, without power supply, indicator or cable.) Infrared Thermometer System 1980-1989