ISO 19662 | IDF 238:2018规定了一种测定牛奶脂肪含量的方法，即酸-丁基滴定法或“Gerber法”。适用于全脂牛奶和部分脱脂牛奶。 它也适用于含有授权防腐剂（重铬酸钾、溴丙醇）的牛奶。 它不适用于福尔马林牛奶，也不适用于经过均质处理的牛奶。

ISO 19662 | IDF 238:2018 specifies a method, the acido-butyrometric or "Gerber", for determining the fat content of milk. It is applicable to whole milk and partially skimmed milk. It is also applicable to milk containing authorized preservatives (potassium dichromate, bronopol). It does not apply to formalin milk, nor to milks that have undergone a homogenisation treatment.