ISO 995:1975
Withdrawn
Potassium hydroxide for industrial use — Determination of silica content — Reduced molybdosilicate photometric method
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09-01-1975
02-27-2019
The method is applicable to products having silica contents exceeding 10 mg/kg. The principle is based on the formation of yellow oxidized silico-molybdic complex in a strongly acid medium, in the presence of boric acid to suppress interference by fluorides. Selective reduction of this complex with a mixture of aminonaphtholsulphonic acid (4-amino-3-hydroxynaphthalene-1-sulphonic acid), sodium metabisulphite and sodium sulphite, in the presence of oxalic acid and in a strongly acid medium so as to suppress interference by phosphates. Photometric measurement of the blue-coloured complex at a wavelength of about 795 nm.
| Committee |
ISO/TC 47
|
| DocumentType |
Standard
|
| Pages |
3
|
| PublisherName |
International Organization for Standardization
|
| Status |
Withdrawn
|
| Standards | Relationship |
| NBN T 03 191 : 1980 | Identical |
| NFT 20 383 : 77 FD | Identical |
| BS 5634:1978 | Similar to |
| I.S. EN 60993:2002 | ELECTROLYTE FOR VENTED NICKEL-CADMIUM CELLS |
| EN 60993:2002 | Electrolyte for vented nickel-cadmium cells |
| CEI EN 60993 : 2004 | ELECTROLYTE FOR VENTED NICKEL-CADMIUM CELLS |
| IEC 60993:1989 | Electrolyte for vented nickel-cadmium cells |
| BS EN 60993:2002 | Electrolyte for vented nickel-cadmium cells |