The small markings or gradations on rulers, thermometers, etc., used as reference lines or divisions for measuring values.
定規の目盛りを正確に読む必要がある。
You need to read the ruler's markings accurately.
温度計の目盛りが赤い線を越えた。
The thermometer's scale went beyond the red line.
ガスコンロは目盛りで火力を調節するタイプだ。
The gas stove is the type that adjusts the flame by a scale.