Reference number
ISO 1389-4:1977
ISO 1389-4:1977
© ISO 2024
ISO 1389-4:1977
Phthalic anhydride for industrial use — Methods of test — Part 4: Measurement of colour after treatment with sulphuric acid
Edition 1
1977-02
1977-02
Retirada
Resumen
The test sample is treated with sulphuric acid solution in a conical flask in boiling water bath for 3 h. The colour is measured by the method specified in ISO 2211. The results are expressed in Hazen units. - ISO 1389, Parts 1 to 11, replace ISO Recommendation R 1389-1970.