If you need to read, write, study or handcraft at night, then an excellent desk lamp is definitely a good companion for you. High-quality desk lamps can greatly improve your study and work efficiency, and protect your precious eyes during long-term study and work.
Learning partner
The table lamps sold in e-commerce and physical stores are of varying quality, and some do not even meet national standards. You need to keep your eyes open to selecting suitable table lamps. Some merchants exaggerate or even falsely advertise the products they sell, while some merchants do not understand the quality of the products they sell, but just copy some information from peers to promote them. There are many mistakes and I am really worried about buying their products.
For example, a certain e-commerce platform sells 70,000 LED desk lamp , the platform sales first, and focuses on promoting to meet national AA-level illuminance , and surface light source ring dual-effect soft light . We go to the introduction page to see the details. The merchant is willing to place the product inspection certificate page on the web page to prove that the product is of excellent quality. However, we can see that the specific information is unclear on the inspection certificate displayed. In addition, some screenshots of the inspection report that meets the national AA-level illuminance are also placed on the website. The specific requirements and test results are displayed on it, but the standards of use are incorrect. Such a test result is credible? Consumers will have big questions.
error standard, the result is credible?
What aspects do we need to pay attention to for an excellent desk lamp? The following is a detailed introduction, which can also be regarded as popular science publicity. After learning the following content, I believe everyone will have a clear idea of how to choose an excellent desk lamp.
1. Color temperature
What is color temperature?
Theoretically, the color temperature refers to the color that the absolute bold body appears after heating from absolute zero degree (-273℃). Bold After being heated, it gradually turns from black to red, turns yellow, turns white, and finally emits a blue light. When heated to a certain temperature, the spectral component contained in the light emitted by the bold body is called the color temperature at this temperature, and the unit of measurement is "K" ( Kelvin ).
We can simply understand it as the color of the light emitted by the desk lamp.
Generally speaking, the higher the color temperature, the whiter the display. If the light is too white, it will be very dazzling to the eyes. However, the lower the color temperature, the yellower it looks. If the light is too yellow, it is not easy to see the illuminated object. For example, candles are generally 1950K, and ordinary incandescent lamps are around 6000K. So when your eyes are directly facing the incandescent lamp, your eyes are very uncomfortable. The color temperature is generally eye-friendly when it is around 4000K, 4500K and 5000K. After all, the color temperature is yellow and soft and will not irritate the eyes.
Different color temperatures
Different color temperatures have different feelings for the human eye. If the desk lamp emits white light of more than 5000K on a night when the surrounding environment is very dark, the human eye will feel very dazzling and very uncomfortable. National standards stipulate that the color temperature of the light emitted by the desk lamp used at night must be below 4000K. If the color temperature of the desk lamp is higher than 4000K, then this desk lamp is not suitable for use at night. It is necessary to mark warning words to inform the user.
So when purchasing desk lamps, you can compare the color temperature of the above picture and try to buy desk lamps with low color temperature or change color temperature.
2.Light-shielding
What is light-shielding?
Light shielding is the surface brightness requirement of all luminous components observed by the user in a normal sitting position. The conventional understanding is that the luminous part of the desk lamp requires a certain amount of light to prevent light from directly shooting into the human eye and causing glare. Of course, the specific requirement is to obtain professional equipment testing. When ordinary consumers buy LED desk lamps, it is best to ask about the height and adjustable range of the desk lamp. Excessively high desk lamps and too low sitting postures affect the light shading, and pay attention to whether the luminous part is exposed excessively, thereby affecting the comfort of the eyes.
test chart for metering
3. Illuminance
What is illuminance?
generally refers to the light intensity. Light intensity is a physical term that refers to the luminous flux of visible light received per unit area. Abbreviated as illuminance, unit lux (Lux or lx).Used to indicate the intensity of light and the amount of surface area of the object being illuminated. A simple understanding is how much light the desk lamp shines on the desktop. The national A-level and national AA-level mentioned above are indicators of illuminance and illuminance uniformity. AA-level should be better than A-level, and the illumination is high, so the lighting effect is good. Below are the indicator requirements
Desk lamp A-level and AA-level requirements
It can be seen that the illuminance of AA-level within 300 mm and 120 angles need to be greater than 500 lux, which is also an international requirement for many reading and writing scenes, such as classrooms, reading rooms, study rooms and other places. The wider the range of the tabletop illuminated by the desk lamp, the greater the illuminance. At the same time, the maximum illuminance and minimum illuminance ratio within a certain range shall not exceed 3, which can be determined as excellent illuminance. Of course, this requires professional equipment inspection. If the merchant can provide a certificate of qualification, it means that the lighting characteristics of this product are excellent. Ordinary consumers can try to observe the light range and the contrast between light and dark to judge the quality of the product's illumination characteristics.
illumination meter test 809Lux
4.Strobe
What is strobe?
Stroboscopic effect is a phenomenon that makes the observed movement of an object different from its actual movement under light that changes at a certain frequency. The strobe effect is caused by flickering of the light source, which is an unstable visual phenomenon caused by light stimulation of the fluctuation of the brightness or spectral distribution over time.
simply means the flickering of light. Low frequency will be felt to the human eye, while high frequency will not have an intuitive feeling to the human eye. Many desk lamps emit light and their eyes cannot feel the flashing, but it does not mean that the desk lamp does not have strobe.
Mobile test method
strobes can cause vision weakness, eye fatigue, blurred vision, and severely it can cause migraine , nausea, and visual confusion. Therefore, strobe damage is relatively high. At the 315th Gala of a certain year, a batch of inferior lamps, including strobes, were exposed. Without professional tools to detect, you can use a mobile phone camera to detect whether the light source has a grille. For example, the lamps obviously have strobes.
5. Noise
Noise is easy to understand. Whether the desk lamp will produce obvious current sizzling sounds or other noises when adjusting the lights of the lights or adjusting the color temperature. The noise generation may be due to the movement of the internal circuit components or the insufficient component parameter capacity, or the noise generated by electromagnetic interference . It is a long time in noise, especially on quiet nights, which will interfere with the user, and may even cause irritability and other emotions, affecting the study work.
Noise of 30 to 40 decibels is a quieter normal environment; more than 50 decibels will affect sleep and rest. More than 70 decibels will interfere with conversation, affect work efficiency, and even cause accidents; working or living in a noise environment above 90 decibels for a long time will seriously affect hearing and lead to the occurrence of other diseases.
6. Power cord
The power cord of the desk lamp is a wire used to power the desk lamp. The state stipulates that the diameter of the 220V input wire is not less than 0.75 square millimeters , and the exposed length of the power cord of the desk lamp is not less than 1.8 meters. It is easy to understand that as a movable desktop lamp, desk lamp has the function of moving or moving. The appropriate length of power cord can give the user a good experience and avoid pulling the plug during the movement, causing danger.
7. Counterweight
There should be heavy objects at the bottom of the qualified desk lamp. The purpose is to give the table lamps relatively good stability. Even if it is used on a plane with a certain slope or the user accidentally touches the lamp head, the lamp will not overturn. Under normal circumstances, you can use your hands to push the highest point of the desk lamp, or place it on a slope not greater than 6 degrees to see if the desk lamp will overturn.
8. A qualified desk lamp with
will have a product label at the bottom. The
tag generally identifies the electrical parameters, trademark, protection level, power, manufacturer and other key information of the desk lamp. The label information of inferior desk lamps is incomplete or has no labels.
PHILIPS Table lamp tag
9. Appearance
Appearance is the most intuitive feeling.The surface of the desk lamp has smooth feel and no sharp edges. The joints at the assembly are small or no seams, and there is no deformation when moving the desk lamp. When you get close to the desk lamp, you will smell it without any obvious odor. This is to simply determine whether the desk lamp shell is made of inferior second-hand plastic. After working on the desk lamp for a period of time, we can touch the base of the desk lamp and the desk lamp head with our hands. The LED light source is a cold light source. The desk lamp with excellent thermal design cannot feel the temperature outside the lamp. If the desk lamp has a relatively hot or hot part, it means that the thermal design of the product is not in compliance with the standard, the lamp life will not be very long, and it may even cause overheating risks.
is written at the end. Of course,
only lists several key points of desk lamps, which are not comprehensive. If the merchant and manufacturer can provide qualified third-party authoritative proof, it is of course the best. The most expensive one is not necessarily the one that suits you the most. After mastering the above points, I believe you can choose the best desk lamp that suits you the most.
Reference:
------------ Baidu Encyclopedia
------------GB 9473:2017
