What is the meaning of "T" for T8 and T5 fluorescent lamps?

T stands for "tube"-tube, and the number behind it actually represents the diameter of the lamp tube. Each "t number" is 1/8 inches. 1 inch equals 25.4 mm, so the diameter of T8 lamp is 25.4 ÷ 8× 8 = 25.4 mm. ..

Common lamps and lanterns are:

1, T 12 diameter 38.1mm; ;

2.T 10 diameter 31.8mm; ;

3.T8 is 25.4mm；; In diameter;

4. The diameter of 4.T5 is16mm;

5. T4 diameter12.7mm; ;

6. T3.5 diameter11.1mm;

7. The diameter of 7.T2 is 6.4 mm..

Extended data:

The traditional fluorescent lamp, that is, low-pressure mercury lamp, uses the principle that low-pressure mercury vapor releases ultraviolet rays after being electrified to make the phosphor emit visible light, so it belongs to low-voltage arc discharge light source.

1974, Philips Company of the Netherlands first successfully developed phosphors that can emit red, green and blue light sensitive to human eyes. The development and application of tricolor phosphors is an important milestone in the development history of fluorescent lamps.

selection principle

1. In any case, T 12 lamps should be replaced with thin tube diameter (tube diameter ≤26mm), that is, T8, T5 and other types, which has obvious energy-saving and environmental protection effects.

2. In any case, tricolor fluorescent lamps should be used instead of halogen powder fluorescent lamps. Tricolor lamps have the advantages of high luminous efficiency, good color rendering and long service life. Although it is expensive (about twice as expensive), because of its high light efficiency, it not only saves energy, but also reduces the operating cost; In addition, because the number of lamps used is reduced, the cost of lamps and ballasts is saved, but the total initial construction cost of the lighting system is reduced.

3. Use of high-power lamps: In functional lighting places (except decorative requirements), long lamps of not less than 4_ (about 1200mm) should be selected, that is, T8 type 36W and T5 type 28W with high light efficiency.

4. Generally, lamps with medium color temperature should be used: the color table of light source (expressed by correlated color temperature) should be selected, and it can be generally determined according to the illumination level unless there are special requirements for building color: in short, the high illumination (> 750lx) should be cold color temperature (high color temperature), and the medium illumination (about 200 ~ 1≤200lx) should be medium color temperature, and the low illumination (.

Because warm colors and light make people feel comfortable in low illumination, but feel hot and dry in high illumination; However, light with cold color temperature feels comfortable under high illumination and dim and cold under low illumination.

The illuminance in most places is between 200 and 750 LX, so it is better to use a medium color temperature light source. Moreover, the light efficiency of middle and low color temperature fluorescent lamps is higher than that of high color temperature lamps, which is also beneficial to energy saving.

References:

Baidu encyclopedia-fluorescent lamp