n.計時；測時；準(zhǔn)時

The accuracy of scientific observation and calculations always depends on the scientist's timekeeping methods. 科學(xué)觀測及計算的精度總是取決于科學(xué)家的計時方法。

The steelyard clepsydra, a special type of clepsydra, had been the chief timekeeping instrument during the Sui-Tang period and the earlier stage of the Northern Song dynasty. 摘要秤漏是一種特殊類型的漏刻，在隋唐及北宋前期曾是司天機(jī)構(gòu)的主要計時儀器。