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LED Light Bulb Terminology

Coloring Rendering Index (CRI) – CRI represents the quality of light and its faithfulness to render colors correctly, that is, to enable us to perceive colors as we know them. The ideal CRI is 100, and some incandescent bulbs approach this level. LEDs and CFLs use different design components in trying to equal the CRI of incandescent bulbs. LED bulbs CRI ratings range from 70 to 95, and the best CFLs have ratings in the mid 80s. The entire line of Viribright A19 bulbs, for example, features a CRI of 90+ Warm White making them one of the highest in the industry.

Correlated Color Temperature (CCT) – is the measure used to describe the relative color appearance of a white light source. CCT indicates whether a light source appears more yellow/gold/orange or more blue, in terms of the range of available shades of “white.” CCT is given in kelvins (unit of absolute temperature). 2700K is “Warm”,  4000K is “Cool” and 6000K is “Daylight”. The typical light color we are used to in indoor home lighting is “warm”, 2700K.

Lumen – a unit of standard measurement that is used to describe the amount of light contained in an area as perceived by the human eye. The more lumens, the brighter the light. You can use lumens to compare the brightness of any bulb, regardless of the technology behind it, and regardless of whether it’s incandescent, CFL or LED.

In practical application, when buying a light bulb, we should look for bulbs which produce more light but consumes less energy. Understanding lumens as a measure of brightness makes it easier to select the most efficient bulb for your application. This is also important

Wattage – The unit of measurement for electrical power is the watt. Wattage represents the amount of work done or electricity consumed per unit time.

Wattage Equivalent – Equivalent wattages were conceived as a bridge between new and old technologies – they tell you about how much light a bulb gives off compared to traditional incandescent bulbs. The values may vary, as it’s not a straightforward correlation. For example, 60W incandescent light bulbs would be equivalent to 6-8W LED bulbs.

Color Temperature – the temperature of an ideal black-body radiator that radiates light of a color comparable to that of the light source. color temperature is used as a method of describing the warmth or coolness color characteristics of a light source.

Lumens Per Watt (LPW) – The ratio of light energy output (Lumens) to electrical energy input (Watts)

Voltage – Voltage (also known as electric potential difference, electromotive force emf, electric pressure, or electric tension) is defined as the electric potential difference per unit charge between two points in an electric field. Voltage is expressed mathematically (e.g. in formulas) using the symbol “V” or “E”.

Base Code –  Light bulb bases also come in a variety of sizes. They are identified by light bulb base codes, with the letter denoting the shape of the base and the number denoting the size. If you find yourself unsure of your bulb’s base compatibility, consult a store associate for advice in finding the best fit.