Cycle per second Cycle per second The cycle per second was a once-common English name for the unit of frequency now known as the hertz (Hz). The plural form was typically used, often written cycles per second, cycles/second, c.p.s., c/s, ~, or, ambiguously, just cycles. The term comes from the fact that sound waves have a frequency measurable in their number of oscillations, or "cycles", per second. With the organization of the International System of Units in 1960, the cycle per second was officially replaced by the hertz, or reciprocal second, "s" or "1/s". Symbolically, "cycle per second" units are "cycle/second", while hertz
Vibration white finger short time. The duration of use of the tool is measured as trigger time, the period when the worker actually has their finger on the trigger to make the tool run, and is typically quoted in hours per day. Vibration amplitude is quoted in metres per second squared, and is measured by an accelerometer on the tool or given by the manufacturer. Amplitudes can vary significantly with tool design, condition and style of use, even for the same type of tool. In the UK, Health and Safety Executive gives the example of a hammer drill which can vary from 6m/s²