Halogen bulbs are designed to run for about 2000 hours — twice as long as a typical incandescent bulb. They contain a filament as the heating element (as do incandescent bulbs), but they also contain a gas. Because they run at higher temperatures, the envelope of halogen bulbs is made of hard glass, or fused quartz, coated in additives to block out the UV rays the halogen produces.
The external coating on halogen bulbs can be damaged by surface contamination (notably fingerprints!) when it heats. Care must be taken not to touch the glass of halogen bulbs when inserting them.
| When inserting a halogen bulb, hold it with a piece of tissue paper or cloth to avoid damaging the bulb. |
You’ll note that all halogen lamps have a protective glass sheath over the bulb, usually held on by metal clips and screws. Undo this with a screwdriver before replacing the bulb.
Many halogen bulbs are fitted with pin fittings. You should be able to pull them straight out, but sometimes the heat of the bulb fuses them a little, so a very gentle jiggle might be in order. Some spotlights have pins that are wider at the base in order to lock into a twist socket. Twist anticlockwise to undo them.
Some halogen bulbs have blades or dimples at both ends of the bulb, which slot into sprung receptors on each side of the lamp head.
Christmas lights often have a wedge connection, which pulls out and pushes in.
Make sure you buy a replacement bulb of the same voltage. Bulb life reduces by half if the transformer voltage exceeds the bulb voltage by 5%. (In a bedside lamp, the transformer is either the big, black, bulky lump on the plug-in socket or is hidden in the bulky base.)
