一、概述在钟罩式气体流量标准试验装置上检定气体流量计,需要准确测量在钟罩内压下,排出一定体积空气所需要的时间。以往,我们采用人工按秒表来计算,不仅操作烦琐,而且检定结果数据的复现性较差。采用数字频率计能够比较准确地测量时间, I. Overview In the bell-type gas flow test device for testing the standard gas flowmeter, the need to accurately measure the pressure in the bell jar, the volume of air required to discharge a certain amount of time. In the past, we used artificial stopwatch to calculate, not only cumbersome operation, but also poor reproducibility of test results data. The use of digital frequency meter can measure the time more accurately,