by....standard ,on ... standard 区别

前者:按标准
Measurable by a common standard.
可用共同标准测量的

Measurable by a common standard; commensurable.
可用共同标准测量的；可共同测量的

Sales by Specification, Grade, of Standard
凭规格、等级或标准买卖

By what standard do you measure it?
你用什么标准来衡量它呢？

able to be measured by a common standard.
能够用共同的标准来衡量。

后者.....恕小弟才疏学浅,还真没见过,不知怎么用

嘿嘿