IS 13106 : 2024/ISO 420 : 1994 Potassium Bromide, Photographic Grade - Specification
NATIONAL FOREWORD
This Indian Standard (First Revision) which is identical to ISO 420 : 1994 'Photography - Processing chemicals - Specifications for potassium bromide' issued by the International Organization for Standardization (ISO), was adopted by the Bureau of Indian Standards on the recommendation of the Electroplating Chemicals and Photographic Materials Sectional Committee and approval of the Chemical Division Council.
Potassium bromide is used in the photographic industry for processing photographic films. Requirements of photographic grade of potassium bromide were earlier covered under Grade 1 of IS 2797 : 1998 'Potassium bromide - Specification (third revision)'. However, in view of the highly specialized nature of its application, it was decided to formulate a separate standard for potassium bromide, photographic grade.
This standard was initially published in 1991 and prescribed the requirements and methods of sampling and test for potassium bromide used in processing of photographic materials. This standard specified the limits for assay, moisture, chlorides, sulphide, heavy metals and iron. Additional requirements for alkalinity, acidity, matter insoluble in water were also prescribed.
Now this standard is being revised by adopting ISO 420 : 1994 on dual number basis.
The text of the ISO standard has been approved as suitable for publication as an Indian Standard without deviations. Certain conventions are, however, not identical to those used in Indian Standards. Attention is particularly drawn to the following:
a) Wherever the words 'International Standard' appear referring to this standard, they should be read as 'Indian Standard' and
b) Comma (,) has been used as a decimal marker, while in Indian Standards the current practice is to use a point (.) as the decimal marker.