by diffraction gratings

Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable > using optical means, i.e. using infrared, visible or ultraviolet light > with attenuation or whole or partial obturation of beams of light > the beams of light being detected by photocells > Forming the light into pulses > by diffraction gratings

Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable (G01D3/00 takes precedence; specially adapted for apparatus giving results other than momentary value of variable G01D1/00) > characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light > with attenuation or whole or partial obturation of beams of light (G01D5/40 takes precedence ) > the beams of light being detected by photocells > Forming the light into pulses > by diffraction gratings