Hipp chronoscope, Neuchâtel, Switzerland,1893-1900
Measurement is the process of estimating the magnitude of some attribute of an object, such as its length or weight, relative to some standard (unit of measurement), such as a meter or a kilogram. The act of measuring usually involves using a measuring instrument, such as a ruler, weighing scale, thermometer or speedometer which is calibrated to compare the measured attribute to a measurement unit. Metrology is the scientific study of measurement.
Electronic device for measuring extremely short intervals of time with great accuracy, such as for determining the velocity of projectiles.