Sometimes it is necessary to write down some important secret information and be sure that no one else can read it. It was for such cases that an ultraviolet pen was created. Use it to write invisible text. You can read it only if you use a special flashlight. A miniature light source emits ultraviolet rays, under which written in invisible ink instantly appears. There are no other options for reading such text.
Appearance and safety
There is no need to constantly carry a special flashlight, as it is already built into the cap of the handle. Such a writing aid looks like an ordinary felt-tip pen or marker with a rod. The cap not only serves as a flashlight for the manifestation of various inscriptions, but also prevents the pen shaft from drying out, and also prevents unusual ink from evaporating.
They include a substance that appears only with ultraviolet radiation. However, you can not worry about their toxicity. Certified pens are absolutely harmless to health.
Source of power
The flashlight works thanks to three small AG3 batteries. When they are used up, they can be easily changed. To do this, unscrew the top of the cap and carefully pull out the block. One set of the cheapest batteries lasts about 2 weeks. If there is a need to use a flashlight often, then it is better to purchase batteries for it more expensive. Quality batteries will have to be changed no more than once every 2-3 months.
The flashlight is turned on using the button on the case. To prevent the batteries from running out of power during the trip, a plastic insulator is inserted between them through a special hole in the top of the handle.
Advantages and disadvantages
The body of the UV handle is made of durable plastic. If she falls even from a great height, nothing will happen to her.
An additional plus is that at any time with the help of a flashlight you can check banknotes for fake. Just shine them with ultraviolet light.
The disadvantages include the inability to replace the rod. After the invisible ink runs out, the pen will have to be thrown away. Fortunately, the market now has a huge assortment of such products. Thanks to a large number of offers, the price has become quite affordable. For example, an ultraviolet pen "Gravity Falls", which has all the properties characteristic of such products, costs about 240-300 rubles. You can find a cheaper option - from 100 rubles.
You can also try to make invisible ink yourself. To do this, take in equal proportions all the necessary ingredients (thick rice broth, sour apple juice, lemon or onion, fresh milk, melted wax) and mix. High-quality inks are also obtained from a few drops of copper sulfate, a spoonful of washing powder, a couple of tablets of aspirin and a small amount of iodine.
Areas of use
How and where can I use a UV pen? There are a lot of areas of its application. Using the pen you can write:
- diary entries that no one should see except the owner;
- secret or love messages intended for only one specific recipient;
- safe cheat sheets, which will be very convenient to use on the exam, because not a single teacher will guess that something is written on a regular snow-white sheet;
- congratulations on postcards (in order to play or surprise the birthday man).
An ultraviolet pen with invisible ink can be an unusual and useful gift for both an adult and a child.