A Rapid and Accurate Photometric Method for Determination of Lead in Small Quantities

Photoelectric Photometers for Use in Colorimetry

“…THE recent development of photoelectric cells (9,19,28) has made it possible to avoid many limitations that characterize the use of photometric colorimeters read by means of direct ocular observation. Some of the photoelectric photometers thus far described have single photocells (1,5,6,7,10,12,(14)(15)(16)(17)(18)21), while others (2,8,4,8,11,18,20,22) have two. The two-celled form seems to the writer to be preferable.…”