Who Invented the Lens Used at the Pigeon Point Lighthouse?Augustine Jean Fresnel (pronounced fray-nell) Fresnel (born May 10, 1788, died July 14, 1827), a French physicist, was commissioned by France in 1822 to develop a better lighting system for the French lighthouses. Rather than try to develop a brighter light source, Fresnel set about designing a better, more efficient method of using the light which 1820's technology could produce. 19th Century lighthouses used silvered-metal parabolic reflectors, placed behind a lamp, to direct the light seaward. This system was not very efficient, and worked poorly as an aid to navigation. Remember that light produced by a lamp, or any source, radiates out in all directions. Fresnel's task was to find the most efficient method to direct all, or nearly all, of the lamp's light rays out to sea. To improve upon the parabolic reflector, Fresnel looked to glass lenses for a method of directing more of the light from a lamp seaward. Molding a single lens to do the job was impractical. A lens suitable for a lighthouse would be far too large to be cast as a single lens. Instead Fresnel designed a system of smaller lens and prisms, arranged in a stair-step configuration. He used this system to bend, fold, and focus the light out to sea. The result was a lens that was able to use about 80 percent of the light available from the lamp! In the case of the lens used at Pigeon Point, about 70,000 candlepower was produced by the original lamp. This type of lens, called a Fresnel  lens, was a technological breakthrough! The new lens was far more efficient in its use of the small amount of light produced by a ?page_id=22000">lard oil lamp. In addition, a Fresnel lens could be disassembled and shipped in sections and configured into virtually limitless numbers of light characteristics, that is, patterns of flashes of light divided by periods of darkness.

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Who Invented the Lens Used at the Pigeon Point Lighthouse?Augustine Jean Fresnel (pronounced fray-nell) Fresnel (born May 10, 1788, died July 14, 1827), a French physicist, was commissioned by France in 1822 to develop a better lighting system for the French lighthouses. Rather than try to develop a brighter light source, Fresnel set about designing a better, more efficient method of using the light which 1820's technology could produce. 19th Century lighthouses used silvered-metal parabolic reflectors, placed behind a lamp, to direct the light seaward. This system was not very efficient, and worked poorly as an aid to navigation. Remember that light produced by a lamp, or any source, radiates out in all directions. Fresnel's task was to find the most efficient method to direct all, or nearly all, of the lamp's light rays out to sea. To improve upon the parabolic reflector, Fresnel looked to glass lenses for a method of directing more of the light from a lamp seaward. Molding a single lens to do the job was impractical. A lens suitable for a lighthouse would be far too large to be cast as a single lens. Instead Fresnel designed a system of smaller lens and prisms, arranged in a stair-step configuration. He used this system to bend, fold, and focus the light out to sea. The result was a lens that was able to use about 80 percent of the light available from the lamp! In the case of the lens used at Pigeon Point, about 70,000 candlepower was produced by the original lamp. This type of lens, called a Fresnel  lens, was a technological breakthrough! The new lens was far more efficient in its use of the small amount of light produced by a ?page_id=22000">lard oil lamp. In addition, a Fresnel lens could be disassembled and shipped in sections and configured into virtually limitless numbers of light characteristics, that is, patterns of flashes of light divided by periods of darkness.

DigitalMeasuring Microscope

3. Angle-measuring eyepiece inspection.① Check the zero position of microscope goniophotometer eyepiece;② Checking the coincidence of the intersection of the crosshairs of the measuring microscope goniometer eyepiece and its center of wide rotation.Operation of the measuring microscope:1. Place the test sample on the measuring table, as far as possible in the center of the glass. 2. Turn the focusing hand wheel of the measuring microscope until the sight is clear, judge the Z thin point by visual inspection, rotate the measuring table and rely on the vertical and horizontal adjustment, adjust the original reference in the direction of Z thin point to coincide with the crosshairs, record the scale value X1 corresponding to the test mark line.

Measuring microscope is a kind of optical measuring instrument equipped with aiming microscope and coordinate table for two-dimensional coordinate dimension measurement. Measuring microscope adopts the transmission and reflection method to make precise measurement on the length and angle of workpiece.

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It is especially suitable for testing of video heads, line widths of large scale integrated circuits and other precision parts, and is an ideal compact and multi-purpose precision measuring instrument. In the article below, we will talk about how to use a measuring microscope.

1.Preparation：Check the safety of the surrounding environment, whether the power supply, voltage, LED light source, grounding wire and so on are correct and solid, should be in accordance with and requirements.2. Check main components of measuring microscope kinematic performance.Measuring microscope table, longitudinal and transverse slide rail, micrometer, microscope arm rail elevation, angle plate rotation and other components, after visual observation and manual test, must confirm the structure is installed reliably, accurate position, operating performance should be comfortable and intact, no loose block and rapid jump phenomenon exists.

3. Adjust the transverse handle, move the measuring table along the X axis, record the reading of the other side X2, the difference between X1 and X2 is the measured value. 4. Rotate the measuring table and measure the readings of each point in sequence.5. When measuring the diameter, move the X and Y axis to read the value respectively.Precautions of measuring microscope1. The use and maintenance of measuring microscope is a strong technical work, the operator should be trained with professional skills, master the necessary operating skills and establish the necessary work inspection system.2. Measuring microscope should be properly and reasonably arranged to use. The storage place of the instrument should avoid dust, dampness, sudden temperature change or containing acidic or alkaline gas environment.3. Measuring microscope optical parts: eyepiece, objective lens, glass table and so on, optical parts of the surface oil dust clean, can be degreased cotton dipped in a little alcohol and ether mixture, wipe gently, do not wipe the lens wool.4. Measuring the microscope maintenance, maintenance, debugging, without technical training do not have the professional skills to disassemble debugging and cleaning and refueling.5. Power system failure, need to cut off the power supply, and then check. Replace the light bulb of transmittance lighting, dismantle the bottom cover and check and replace.