How to distinguish a double mirror from a single mirror?

The distinction between a double-sided mirror and a single-sided mirror can be comprehensively judged by listening to the sound, brightness and flashlight in the dark with your fingers.

First, the finger judgment method

See if there is a distance between your finger and the finger in the mirror. A single-sided mirror with a certain distance; Double mirrors, fingertips seamlessly connected. But it is not suitable for all double mirrors.

Principle: Because an ordinary mirror is glass with a reflective layer in front, the reflective layer is generally plated on the back, so it is separated by the thickness of a piece of glass.

Second, knock on the mirror to listen to the sound.

Knock on the mirror and listen to the sound. When you find that the sound is hollow and there is a slight echo, then this mirror may be a double mirror.

Principle: The thickness and material of double mirror and single mirror are the same. But in general, the back of a double-sided mirror is empty, while most of the single-sided mirrors are mounted on the wall, and there is a wall on the back. Theoretically, knocking method can be distinguished, just as we use knocking method to check the hollowness of the wall when we hand in the new house.

Third, the brightness judgment method

Stick your little makeup mirror on the mirror to compare the brightness of the image and look at your face. If the brightness of the big mirror is obviously lower than that of the small cosmetic mirror, be careful.

Principle: A double-sided mirror uses about 50%~70% reflective layer, so it is darker than a single-sided mirror. Take out the cosmetic mirrors you carry with you and compare them together to see if there is a big difference in brightness.

Fourth, look with a flashlight in the dark.

Turn off the light and shine the flashlight in the direction of the mirror.

Principle: A feature of double mirrors is that they can see the bright side from the dark side. If you turn off the light on your side, you will see the opposite. So just turn off all the lights, point the flashlight at the mirror or stick your eyes on the mirror, block the light with your hands, and look carefully at whether there is anything behind the glass.

Finger judgment method cannot be used to identify double mirrors in all cases;

The police said that the method of "identifying double mirrors" circulating on the Internet is not reliable. Double-sided mirrors are made of ordinary glass with vacuum coating and a film of chromium, aluminum or iridium, which can reflect most of the projected light back, and are often used for monitoring and peeping by criminals. One side of the double mirror looks like a mirror, and the other side is ordinary stained glass.

The method of detecting the finger approaching the mirror is not suitable for all double mirrors, because as long as a layer of glass is added in front of the double mirrors or a "sandwich" is coated in the middle of the glass, this method will not work. At present, many double mirrors will add glass in front. Therefore, the "finger method" cannot be applied to all situations.

Public trust. Com- netizens say that Nanjing has a "lens" of hotels? The identification method of network transmission is unreliable.

Refer to the above content: Baidu Encyclopedia-One-sided Mirror

Baidu encyclopedia-two-way mirror