News. 1  Proctorâs and Paceâs Chapel joined to make one church. 2  Prepare for the unexpected repair bill. 3  Managing your spring allergies.  Health 1  Inspections. âItâs our people that make the differenceâ.  MADSOCIAL: Women of the Frontier returns to Fort 1  Boonesborough. Daniel Boone memorabilia collection  opens.
A micrometer is a measurement device incorporating a calibrated screw used widely for precise measurement of small distances in mechanical engineering and machining as well as most mechanical trades. The first micrometer was developed by Jean Laurent Palmer of Paris in 1848.
An ammeter is a measuring instrument used to measure the electric current in a circuit. Electric currents are measured in amperes (A), hence the name.Instruments used to measure smaller currents, in the milliampere or microampere range, are designated as milliammeters or microammeters.n a hot-wire ammeter, a current passes through a wire which expands as it heats. Although these instruments have slow response time and low accuracy, they were sometimes used in measuring radio-frequency current.