It seems that liquid can also be accurately weighted (http://bbs.instrument.com.cn/shtml/20110321/3196859/ dilution by weight or by volume)

poorlittle老师说得对，固体和液体都可以称量的，我只是为了区别这里的weighed和measured，解释得有点片面

度量衡are measurement of length,volume and weight respectively.

“accurately weighed or accurately measured” can be translated as精确地衡或量, 但这显然不是行内习惯用语, 还是“ 精确称量或精确量取”较为人所接受。

[ Or“精确称取或精确量取”? where 称取=measurement by weigh; 量取=measurement by volume. ]

By the way, it seems that there is definition for “accurately weigh”( ±n%? ) in the Pharmacopoeia.

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是的，中国药典的习惯用语是“精密称定”，系指称取重量应准确至所取重量的千分之一；
美国药典这样说的：Unless otherwise specified, when substances are to be “accurately weighed” for Assay, the weighing is to be performed with a weighing device whose measurement uncertainty (random plus systematic error) does not exceed 0.1% of the reading. 两国药典的说法好象有差别？