The length of the eyeball (either longer or shorter), changes in the shape of the cornea, or aging of the lens can cause refractive errors. Most people have one or more of these conditions. The cornea and lens bend (refract) incoming light rays so they focus precisely on the retina at the back of the eye.
BF series Composite strain gauge. This gauge is designed for measurement on composite materials. It has a specially designed grid configuration to reduce the tightening effect of the gauge to the specimen. As the temperature compensation is available for material with thermal expansion coefficient of 3, 5 or 8ppm/Â°C, this series is recommendable for ceramic, carbon, and composite materials.
Air filter kit-adapts any standard MagnehelicÂ® gage for use as an air filter gage. Includes aluminum surface mounting bracket with screws, (2) 5 ft (1.5 m) lengths of 1/4 aluminum tubing, (2) static pressure tips & (2) molded plastic vent valves.here are two ways to measure air flow in process ducts. The most common means is the use of a Series 2000 MagnehelicÂ® Differential Pressure Gage. This gage can be ordered with a square root output that will read in flow units. You will have to specify the maximum differential pressure at your desired flow rate.