Magnifiers are inspection or assembly instruments that enlarge the image of a product or feature. The level of magnification (generally less than 50X) differentiates magnifiers from their higher power cousins, microscopes. Magnifiers are available in many configurations such as handheld, loupe, linen or folding, binocular, desktop, or headband styles. They are used in a wide variety of applications, including assembly, electronics manufacturing (PCBs), industrial inspection, precision machining, tool & die work, jewelry and gemology, medical and life sciences, textiles, vision or sight assistance, forensics, photography, and document analysis.
Magnifiers have various configurations and mountings available. These include arm, boom and clamp, bar, rule and sheet, binocular, desktop stand, folding and linen, floor stand or mount, handheld, headband and visor, loupe, magnetic base, pocket, screen magnifier, and video and digital. Arm, boom and clamp magnifiers are mounted on a rigid boom, flexible gooseneck, or articulating arm. This style of magnifier is used for inspection, jewelry work, assembly, or electronics manufacturing applications, where the ability to easily position the magnifier and provide two free hands is an asset. Bar, rule, or sheet magnifiers are used to examine documents, photographs, or textiles. They function by placing a plastic or glass lens on top of the item that is being examined. Generally, hemispherical or Fresnel lenses are used in conjunction with these magnifiers. Rule magnifiers have a scale printed or inscribed on a surface of the magnifier to allow for more precise measurements. Binocular magnifiers are colloquially known as "headlights." Folding and linen magnifier classification includes styles where the lens folds into the body for protection, or the lens or the body collapses to a more compact size for portability. A variety of folding magnifiers are available, generally in handheld or desktop configurations. Box-like folding magnifiers that mount on a desktop are often referred to as linen magnifiers. Headband or visor magnifiers are worn on the head, like a hat or pair of glasses. Some varieties allow the user to flip lenses into and out of place to change the magnification level. Loupes are commonly used by jewelers, a loupe is a small magnifier held in the eye socket to allow for intense scrutiny of an object. Some styles are handheld or clip onto glasses. Screen magnifiers are simply flat screens that are placed in front of a computer monitor, video or television screen, to magnify the image. Video and digital instruments include all magnifiers that capture an image digitally though a video camera or CCD, and then electronically magnifying the image display on a screen. The resolution of the initially captured image limits the level of magnification.
The most important specification of magnifiers is the magnification. This is the number of times the image is magnified. Common features of magnifiers include bifocal lenses, illumination, ESD safe, scale or comparator reticles, variable magnification, and work holders or manipulators.
Applications that use magnifiers include assembly, document and photograph inspection, electronics manufacturing, forensics, industrial inspection, jewelry and gemology, medical and life science, vision aid, tool and die or machinist, and textiles.