零点
主尺は上側が0.1.2.…と1mmごと、下側は0.5mmずれて目盛り線が入っている。
副尺は0.01mmごとに目盛り線が刻まれており、一回転で0.5mm。
目盛り線が合わない場合の千分台は、だいたいしか分からないので目測で読む。
主尺を読むと4.5mmとなる。
5mmの線が見えているが副尺の目盛りを考えると5mmではない
次に副尺を読むと0.49mm、目盛りの間をも読むと0.488mmとなり、主尺と副尺を合計して4.988mmとなる。
かえり等の有無を確認
有効期限ラベルの確認
Zero point.
On the main scale, graduation lines are marked in increments of 1mm as 0, 1, 2, … in the upper side and ones in the lower side are marked with displacement of 0.5mm.
On the vernier scale, graduation lines are marked in increments of 0.01mm and it moves 0.5mm with one rotation.
A value of parts per thousand, which is seen when scale marks do not match others, should be read by eye as the only approximate value can be obtain.
The scale reading of the main scale is 4.5mm.
The 5mm line can be seen but considering the tick mark of the vernier scale it is not 5mm.
Next, the scale reading of the vernier scale is 0.49mm and if reading the interval of the graduations, it is 0.488mm. The total of the main scale value and the vernier scale value is 4.988mm.
Check bumps etc.
Confirm an expiration date label.
