by observing photo-reactions between gases

Introduced: September 1968

Full Title

Full titles differ between systems:

IPC:

Photometry, e.g. photographic exposure meter > using chemical effects > by observing photo-reactions between gases

CPC:

Photometry, e.g. photographic exposure meter (spectrophotometry G01J3/00; specially adapted for radiation pyrometry G01J5/00 ) > using chemical effects > by observing photo-reactions between gases

No child classifications to compare. This is a leaf node in both IPC and CPC.