Cleaning a TV screen seems easy. Most modern HDTVs have special coatings on their surface that can be ruined by strong cleansers. But at some point, every HDTV screen needs a good cleaning. The following is a sampling of the warnings in various owner's manuals from this year's HDTVs. Double check your owner's manual, as each TV is slightly different, and may require different methods.LG: Clean only with a dry cloth. When cleaning, unplug the power cord and wipe gently with a soft cloth to prevent scratching. Do not spray water or other liquids directly on the TV as electric shock may occur. Do not clean with chemicals such as alcohol, thinners, or benzine.Panasonic: The front of the display panel has been specially treated. Wipe the panel surface gently using only a cleaning cloth or a soft, lint-free cloth. If the surface is particularly dirty, after cleaning up the dust, soak a soft, lint-free cloth in diluted, mild liquid dish soap (1 part mild liquid dish soap diluted by 100 times the amount of water), and then wring the cloth to remove excess liquid.

Use the cloth to wipe the surface of the display panel, then wipe it evenly with a dry cloth of the same type until the surface is dry. Do not scratch or hit the surface of the display panel with fingernails or other chard objects. Furthermore, avoid contact with volatile substances such as insect sprays, solvents, and thinner; otherwise, the quality of the surface may be adversely affected. Samsung: The exterior and screen of the product can get scratched during cleaning. Be sure to wipe the exterior and screen carefully using the cloth provided or a soft cloth to prevent scratches. Do not spray water directly onto the product. Any liquid that goes into the product may cause a failure, fire, or electric shock. Clean the product with a soft cloth dampened with a small amount of water. Do not use a flammable liquid (e.g. benzene, thinners) or a cleaning agent.Sony: Wipe the LCD screen gently with a soft cloth. Stubborn stains may be removed with a cloth slightly moistened with a solution of mild soap and warm water.

If using a chemically pretreated cloth, please follow the instruction provided on the package. Never spray the water or detergent directly on the TV set. It may drip to the bottom of the screen or exterior parts and enter the TV set, and may cause damage to the TV set. Toshiba: Clean only with a dry cloth. Gently wipe the display panel surface (the TV screen) using a dry, soft cloth (cotton, flannel, etc.). A hard cloth may damage the surface of the panel. Avoid contact with alcohol, thinner, benzene, acidic, or alkaline solvent cleaners, abrasive cleaners, or chemical cloths, which may damage the surface. What a surprising consensus among the major TV manufacturers. Many new TVs ship with a soft cloth to clean the screen. If you've tossed/lost this cloth, it's similar to what comes with glasses and sunglasses. These are the strict and likely extreme views of the manufacturers. The vast majority of every owner's manual is copied from other owners manuals. For example, the delicate nature of the front of an LCD screen is very different from the glass front of a plasma.

That's not to say you shouldn't take caution either way, but there are other options...Screen cleaners So why not Windex? Regular Windex is formulated for glass windows, plus a few other surfaces. It contains ammonia and alcohol, not the friendliest of chemicals. S. C. Johnson doesn't explicitly say not to use Windex on HDTVs, but it offers Windex Electronics wipes and cleaners, so infer what you will. The better screen cleaners will clearly state that they do not contain alcohol or ammonia.average cost of air duct cleaningAt last count, I found eleventy-billion companies making HDTV screen cleaners. air purifiers amazon.co.ukAlmost all of these are something like 99 percent water, 1 stuff stuff. electronic air cleaner detergent

A few years back I tested a handful and found them, on average, to work well enough. Not sure any are worth $20, but for $10 or so, why not? You can also use it for your laptop, tablet, and cell phone screens. Plus, they come with a micro-fiber cloth. If they don't clearly state they don't contain alcohol and ammonia, skip them.Bottom line When it comes down to it, TVs screens are expensive and fragile. Why risk marring their surface by using cleaning methods the companies themselves don't advise? Get a nice micro-fiber cloth (if your TV didn't come with one), and use that. For the next step up of smudges, try just water. Don't press too hard. There's less than a millimeter between your finger and a broken TV. If your kids/spouse really went at the screen in some sort of paste-enabled drunken rage, try a tiny bit of dish soap in water. I'd use Panasonic's recommendation of 1 part per hundred, but start with less (i.e. more diluted) and see if it works. If you're not much of a chemist, screen cleaning kits are fine.

Remember, though, like all TV accessories, the store is selling them because they probably make more profit on that $20 kit than the $1,000 TV. Got a question for Geoff? First, check out all the other articles he's written on topics like why all HDMI cables are the same, LED LCD vs. plasma, active versus passive 3D, and more. Still have a question? Send him an e-mail! He won't tell you what TV to buy, but he might use your letter in a future article. You can also send him a message on Twitter @TechWriterGeoff or Google+.The best way to avoid having to clean the lenses on your microscope is to use it carefully and keep it covered whenIf a lens gets dirty or gummed up, here's what you do. Only clean your microscope lenses when they are dirty and use the proper materials! Try to locate the dirt.  Is it on the eyepiece lens or objective lens?  If you see a spot when looking in the microscope and you see it at all powers it's probably on the outside ofIf your eyepiece lens turns, turn it and see if

If so, the dirt is on the eyepiece lens.  the spot doesn't move when you turn the eyepiece lens and you see it at all powers then  the dirt is internal and you should probably have it cleaned by aIf you only see it at one power, the dirt is most likely on that particular objective lens. you need more air pressure, you can use the compressed air cans (like Radio Shack #64-4350). not use any sprays with cleaners.  Once blown clean, lightly wipe the lens withThese are lint-free paper tissue made for use with fine machinery andThey are made by Kimberly-Clarke, (who also makes Kleenex), and are available in art supply and larger paper supply stores among other places. The proper motion to use when working with these tissues is to "swipe" the lens in one direction rather than rub in a circularDo not clean lenses with ordinary cloth, paper towel, or Another good cleaning tissue is Kodak Lens Tissue (available at photo stores) In lieu of a

brush, you can use the paper. Roll the tissue into a tube and tear it in half, with the feathery torn ends together. Use several for veryA regular lens brush can hold grit and cause scratching. If the grime is still there, you will need to use a solvent. When using solvents, put a drop or two on the paper then hold it against the lens for a few seconds to dissolveDistilled water is the first solventIf that doesn't work,  try alcohol.   Isopropyl alcohol is one of the best solvents but it must be at least 90%+ pure (do not use rubbing alcohol, 30%Try Walmart for the full strength variety). Everclear which is grain alcohol (you must be 21!) can also be used but it doesn't do as well in dissolving crud (although it does mix with orangeIf you have something like Balsam stuck on the lens, you must resort to a stronger solvent like Acetone should never be put on plastic parts as it dissolves most paints and plastics. makes a lens cleaning solution and Edmund Scientific carries one called Lens Luster

Some people swear by a solution called ROR, although I've neverYou can find it at here. When adding the solvent, put only a small amount on the kimwipe and always apply it from the underside going upward to the lens. keep the liquid from running down into the lens. Do not remove the lenses from the instrument unless absolutely necessary and never soak even the tip of an objective lens in a container of solvent!  dissolve the cement used to hold the glass lenses in place. Sometimes objective lenses get gunked up with glycerine, blood or other albuminous material.  It can be removed with lens paper dipped in a weak ammonia solution (one dropper full of household ammonia in 1/2 cup water). If you are using a 100X objective with immersion oil, just simply "swipe" the excess oil off the lens with a kimwipe after use. Occasionally dust may build up on the lightly oiled surface so if you wish to completely remove the oil then you must use an oil soluble

For the Cargille Type A or B immersion oil, you can use Naptha, Xylene, or turpentine (use very small amounts on the kimwipe). Do not use water, alcohol or acetone as the oil is insoluble to theseConsult the MSDS info that is supplied with your immersion oil to see what solvents are recommended.   To remove other oily substances, we recommend using the detergent called Wisk and prepare a solution of 1 part Wisk to 100 parts Periodically inspect the power cords and plugs for safety and have aProfessional cleaning and adjusting should be performed whenever necessary at an optical shop specializing in microscopes. Unless you are a professional do not attempt to clean or adjust the inner optics of your microscope. When your microscope is not in use, it should be placed in a case or covered and stored in a safe area where it won't get knocked over or stolen. If you have a heavy duty vinyl dust cover, double cover your microscope with it and a plastic shopping bag.