所有液体比重计的出厂鉴定、周期检定、检验和专门的检查都是用一等和二等标准密度计来进行的。目前苏联标准密度计的数量达到二万件以上。一等标准液体比重计首先是按照检定系统表用专门检定用液体与基准液体比重计直接对比的方法来检定。基 All liquid hydrometers factory identification, periodic verification, inspection and special inspections are carried out with the first and second-class standard densitometer. At present, the number of Soviet standard density meters reaches more than 20,000. First-class standard hydrometer First, according to the verification system table with a special test with a reference liquid hydrometer direct contrast method to test. base