Hand lamp
A hand lamp is a portable, mains-independent lamp with a reflector that is usually matched to the high beam characteristics. By inserting a diffuser or by sliding or rotating the reflector, the characteristic can be changed to ambient light in the close range. Most Handscheinwerfer be a battery or a battery with power supplied. However, there are also variants for connection to the vehicle electrical system (e.g. via a cigarette lighter).
The light is usually generated using a halogen lamp , but there are also types with a conventional incandescent lamp or with one or many LEDs . Some models also use a gas discharge lamp which, like LEDs, offers a higher degree of efficiency and thus a longer burn time for a given battery capacity.
A hand lamp differs from a flashlight not only in the higher light output and the larger design. Because of the great dangers that threaten an unexpected light failure, especially in industrial environments (construction sites, forests, abysses, open shafts, sharp-edged and pointed objects, chemical hazards), many professional hand lamps (unlike simple flashlights) are equipped with special safety functions:
- Automatic switch-on:
- In combination with a charger integrated into the device or designed as a base , the hand lamp switches on automatically in the event of a power failure and can thus be easily found in the event of a total failure of the normal lighting in spite of the darkness and used to cope with the emergency. The associated chargers are therefore designed for long-term charging without damaging the batteries.
- Thread breakage:
- The devices often have two incandescent lamps (main and economy light). If the filament of the main lamp breaks, the secondary lamp switches on automatically so that there is never complete darkness and disorientation.
- Explosion protection:
- Many hand lamps are so-called explosion - proof versions, ie the appropriate gas-tight housing prevents any ignitable gases or dusts in the vicinity from being caused to explode, which can be caused by sparks on the switch or bursting or hot light bulbs. Such specially approved devices are identified by standardized stickers with the black letters Ex on a yellow background or a clearly visible imprint with the letters Ex .
- Hazard warning light:
- Many hand lamps also have a flashing function which, in conjunction with colored front-mounted windows, enables them to be used as a hazard warning flashing light.
- Operating time:
- High-quality devices have a battery capacity that allows several hours of use of the main light and up to 20 hours of operation of the economy light when fully charged.
- Charge level indicator:
- Some high-quality devices are equipped with an LED-based charge level indicator, which enables an assessment of the expected lighting time so that the return journey can be started in time in dangerous environments.
- Models with a tiltable headlight head enable z. B. a stable alignment of the light on the job during repair and interference suppression, the device can be parked nearby so that both hands are free.
In Germany, the “ Henkelmann ” -shaped hand lamps made by Cooper Crouse Hinds (formerly CEAG ) and Bosch / Eisemann are particularly popular among professional users . Simpler models for the household are also offered in hardware stores.