GOST 8.135-1974 State system for ensuring the uniformity of measurements. pH measuring. Standard-titres material dose for making 2nd class standard buffer solutions. Specifications
GOST 9147-1980 Laboratory porcelain ware and apparatus. Specifications*, 2024-04-17 Update
GOST 30648.5-1999 history
1999GOST 30648.5-1999 Infant milk products. Method of active acidity determination