Q-ty per pack
The number of lamps supplied in the kit. Indicated if it is a
set of several products ; the most modest such kits include only 2 light bulbs, in the most extensive this number can reach 10 pieces.
Anyway, all lamps included in the set are of the same type and characteristics. And such a complete set is convenient, first of all, because the set is cheaper than the same number of lamps bought one at a time.
General-purpose bulb
A parameter that describes the brightness of the lamp compared to a general purpose lamp (LON — a conventional incandescent bulb). Simply put, an analogue of LON is the power of an incandescent lamp, which is equal in brightness to the model in question. For example, a
75W LON analogue means that the lamp glows as brightly as a 75W incandescent lamp.
This parameter appeared for the convenience of evaluating and comparing different types of lamps in terms of brightness. Data on the luminous flux say little to the average user, and it makes no sense at all to evaluate the brightness by power — different types and even different models of lamps of the same type can differ markedly in efficiency. On the other hand, many users are accustomed to dealing with incandescent lamps, and comparison with such a lamp is familiar and understandable to them. In addition, the LON analogue allows you to compare different types of lamps, and it can also be very convenient when replacing incandescent lamps with more economical ones: for example, if 100-watt lamps were used in the chandelier, then the new lamps must have an LON analogue of
at least 100 W — otherwise they may be too dim.
Scattering angle
The angle of light dispersion is the space in front of the light bulb, which is illuminated by the source itself, and not by the light reflected from the walls and interior items. In other words, the angle of light scattering determines the zone of the best illumination. Classic incandescent bulbs demonstrate the widest dispersion angle — they shine almost 360˚. LED spotlights have the smallest illumination angle, which are able to illuminate well only the area directly under the bulb — the scattering angle in such cases is about 15˚. Of course, a large angle of light scattering is not always needed. Working in the evening at the table, you need light only in front of you, so as not to disturb anyone. For spotlights that light up only small objects in front of them (a painting, sculpture, bas-relief, etc.), the scattering angle can even be from 4 °. As for the top (general) lighting, in this case it is better to choose something with a wider dispersion angle. These bulbs provide extremely uniform illumination.
Color rendering index (Ra)
The parameter characterizes the degree of correspondence between the natural color of an object and the visible color of this object when it is illuminated by a given light source. The color rendering index Ra (also known as CRI from the English Color Rendering Index) is expressed as a number from 1 to 100. A low index means that colors look dull or unnatural, a high index indicates bright and natural color rendering. In fact, many manufacturers manipulate the value of the color rendering coefficient for their own benefit. After all, ordinary buyers cannot check the reliability of this indicator without using a specialized spectrometer.
Energy class (new)
Energy class according to the new European standard applicable from 2021.
In general, the energy efficiency class indicates how economical a light bulb is compared to other models with similar characteristics. In the old system (current until 2021), the most energy efficient class was designated as "A+++"; however, the development of technology inevitably leads to the emergence of even more economical devices, for which even more "pluses" would have to be added. To simplify marking, it was decided to switch to a new notation system. That is, manufacturers returned to the previous indices from G to A, where A is the most energy efficient indicator. The new classes D, E, F and G, respectively, became the approximate equivalent of the old classes A+++, A++, A+ and A. At the same time, the requirements for class A in the new standard are very high, its achievement is still planned in the foreseeable future.
Claimed running time
The service life of the light source claimed by the manufacturer is implied, during which the illuminator is able to generate the claimed brightness and temperature colour spectrum. It is believed that light-emitting diode (LED) bulbs have the longest service life — their working life can be 10,000 — 50,000 hours (
50 years of operation), depending on the modification of the bulb. But this parameter cannot be regarded as a guarantee, since
a lamp with an operating time of 25 years can work less, and maybe even more, than
a lamp with a "life" of 30 or even
35 years. In second place are energy-saving fluorescent light bulbs that are capable of generating daylight — the service life of such is in the range of 2000 — 20,000 hours. The average service life of halogen bulbs is about 2000 — 4000 hours, but when the power supply is equipped with a soft start device, it can be almost doubled. In last place are classic incandescent bulbs, the service life of which is within 1000 hours.
