Diving lamp
The dive light , even dive light , with a battery or battery -operated hand lamp in a watertight and pressure-resistant housing for use in diving .
use
The diving lamp is used in particular as lighting for night and cave dives, but also for daytime dives. B. generally for color rendering , for illuminating crevices or underwater films.
With increasing depth, water first absorbs the red, later the yellow and green spectral components of daylight . Red is no longer noticeable at a depth of 5 m. The diving lamp makes it possible to view an object in full color even at greater depths. Since water absorbs light more strongly, the light intensity should be higher than with lamps for use on land.
Bulbs
LED and halogen lamps are common sources of light . In addition, get gas discharge lamps (HID and Xenon lamps) and light bulbs used.
In relation to size and weight, LED lamps are very bright and have a longer lighting time than halogen lamps, for example. In LED Torches usually be cold white LEDs installed, the light appears bluish and red color rather poorly reproduces . However, diving lamps with neutral white or warm white LEDs are also available. Halogen light, on the other hand, is always warm white, has a slightly yellowish glow with a high color rendering index in which the colors come into their own under water. However, the light range of halogen lamps is reduced compared to LED and xenon lamps with a higher color temperature.
Lamp shapes
A distinction is made between different lamp shapes in terms of use and function:
- Tank lamp: a diving lamp originally from the field of technical diving with separate components, the lamp head and the battery tank, connected by a waterproof cable; the battery tank is usually attached to a buoyancy compensator or compressed air bottle , while the lamp head is usually attached to the forearm or with a Goodman handle on the back of the hand.
- Hand lamp: as main light: lamp head and batteries or accumulators in one housing. The lighting time of a battery charge is usually shorter than that of tank lamps, therefore particularly suitable for dives of up to an hour.
- Headlamp: worn attached to the mask or helmet. Not common among recreational divers. More common among wreck or cave divers and professional divers.
- Backup lamp: small hand lamp as a reserve lamp in the event of an accident with the main lamp, particularly long lighting time. Should not be operated with batteries.
Diving lamps usually have a reflector, a kind of curved mirror , that directs the light emitted from the side towards the front. Depending on the shape of the reflector used, the following lamps can be distinguished:
- Spot lamps: Diving lamps usually have a spot reflector with a beam angle of approx. 5 ° to 15 °, which bundles the light.
- Flood lamps: Flood reflectors with a larger beam angle are used in particular as photo or film light.
In the case of hand lamps and tank lamps, the reflector can usually be changed so that the right beam angle can be selected for the respective use.
Ferromagnetism
Partial large are in Torches nickel or - iron -containing NiMH - respectively, lithium iron phosphate batteries installed as an energy source. The strongly ferromagnetic iron or nickel can cause a deviation in the needle of a compass that the diver carries with him for navigation . The same effect is caused by magnets, which are often attached to diving torches in order to switch them on and off using a reed relay . A reed relay has the advantage that no bushings are necessary through the housing, which would have to be sealed off because it can be switched through the wall with a magnet .
