How to check whether the hotel mirror is a double mirror?

Usually, a double mirror can be understood as that people outside can see you through the mirror, while you can only see yourself when you look in the mirror. So how to identify whether a mirror is a double mirror?

1, finger judgment method: one finger can try! It's simple. See if there is a distance between your finger and the finger in the mirror. Normal mirror, with a certain distance; Double mirrors, fingertips seamlessly connected.

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.

Disadvantages: please note that just as the reflective layer of a mirror can be plated on the back of the mirror, it can also be plated on the front of it. The semi-reflective film of two-way glass can also be set at the front and back arbitrarily, or even sandwiched between two pieces of glass like a sandwich. When the semi-reflective film is attached to the front of this "mirror", it can be identified by the "finger method", but it will fail in other cases.

2, hand brightness judgment method: The double mirror uses about 50%~70% of the reflective layer, so compared with ordinary mirrors, the double mirror is darker. Take out the cosmetic mirrors you carry with you and compare them together to see if there is a big difference in brightness.

Disadvantages: this method is easy to misjudge, there may be color difference between mirrors, and human eyes have different sensitivity to light, so it is necessary to carry mirrors with you.

3, the enemy is clear and I am dark "method: turn off all the lights, touch the mirror with a flashlight or stick the mirror with your eyes, block the light with your hands, and look carefully at whether there is anything behind the glass, you can tell.

4. "Knock on the mirror to listen to the sound" method: After knocking on the double mirror and an ordinary single mirror respectively, you will find the difference: the sound of the double mirror is full, while the sound of the single mirror is thin.

Disadvantages: Sometimes, due to the hardness of the mirror, you can't hear the difference of sound when knocking, and everyone's hearing is different, so this method may not be effective.