ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 18, Number 1
JKCSEZ 18(1)
February 20, 1974 

A photometric probe that can be immersed in liquid has been prepared by sealing a phototransistor with a collimating lens in a glass tubing water tight. Due to the directional sensing property of the probe, it has been successfully used in photometric titrations. Thus, when the probe is immersed in the titrand solution vertically and a light source is placed underneath the beaker containing the titrand, the relative absorbance of the solution can be measured without shielding from the room light.