There are two purposes (ways) to use an electronic balance; one is to measure out a predetermined amount of powders, liquids, and the like (hereinafter called “measuring-out mode”), the other is to weigh one (or plural) mass (hereinafter called “normal mode”).
Generally speaking, in the measuring-out mode, the precision of the amount to be measured out is allowed to be less accurate than that of the balance, but the response time should be short. However, when the weight of the amount which was measured out is measured in the normal mode, it is more important to ensure the accuracy of the measurement than to shorten the response time.
Conventional electronic balances show an averaged measurement data from constantly obtained data at certain time intervals corresponding to the response time in order to show a stable weight value. However, the certain time to average the measurement data is intuitively shortened or lengthened by a user in accordance with the measurement mode. Such electronic balances have a measuring room in which a measuring pan is surrounded by a windshield in order to prevent the influence of convection and other factors in a measurement environment. However, due to the door's opening and closing motion, the convection within the windshield can take place after the door is closed. This problem is particularly serious when the balance is a so-called analytical balance with the smallest display of 0.01 mg or 0.001 mg for measuring a small sample amount.
[Patent Document 1] Japanese Unexamined Patent Application Publication No. H10-19642
[Patent Document 2] Japanese Unexamined Patent Application Publication No. 2003-156386