Certified Ophthalmic Technician (COT). The Certified Ophthalmic Technician is the second core designation level confirming knowledge in 19 specific content areas specifically designed to test the certified ophthalmic assistant or program graduate who intends to advance their career in the eye care field.
The original spinning jenny used eight spindles instead of the one found on the spinning wheel. A single wheel on the spinning jenny controlled eight spindles, which created a weave using eight threads spun from a corresponding set of rovings. Later models had up to one-hundred and twenty spindles.
How Pneumatic Engine Governors Work. The speed-sensing device on a pneumatic governor is a movable air vane, made of metal or plastic. This small engine part registers the change in air pressure around the spinning flywheel. The pneumatic governor also relies on one or two springs to pull the throttle toward the open position.