... : about 1.0kg YD440 Rotation Speed Monitor 1. Brief Introduction: YD440 rotation speed monitor (microcomputer speed measurement instrument) is a ... angular velocity etc. The display device can be widely used in chemical, metallurgy, energy, light industry, textiles, electronics, and ... unit, decade, hundred's place, kilobit, ten thousand place flash in sequence. 4) The instrument including A, B, C, D ...