Sealed for water resistance

A waterproof flashlight is a sealed luminaire that is protected against ingress of water (and of course dust). The high watertight integrity of the flashlight allows you to have dependable illumination in an environment where the luminaire may be subject to water penetration due to immersion in water or exposure to rain, snow, fog, moisture or splashing water. Waterproof flashlights are indispensable tools used outdoors for search-and-rescue missions, field work, law enforcement, security night patrols, military operations, maritime applications, and sports and recreational activities such as hiking, camping, fishing, cycling, climbing, boating and hunting. Designed to withstand the rigors of demanding outdoor environments, waterproof LED flashlights deliver safety and reliability where they matter most and also the breathtaking benefits of LED lighting in an uncompromised state of readiness.

LED flashlights are moisture sensitive systems

LED flashlights are complex systems whose operation heavily relies on moisture sensitive components such as the LEDs, batteries, metal core printed circuit boards (MCPCBs), driver and control circuitry. LEDs are p-n junction semiconductors which are comprised of a multiple-quantum-well (MQW) active layer interposed between a n-doped GaN layer and a p-doped GaN layer. When a p–n junction is biased in the forward direction, charge carriers (electrons and holes) are injected into the MQW active layer where they recombine to generate light. The monochromatic light produced through injection electroluminescence is partially or completely converted by phosphors to create broad-band electromagnetic radiation which is perceived as white light.

Hydrothermal ageing due to the penetration of moisture is known to be a major life-limiting and degradation-accelerating factor in the phosphor-converted white LEDs. The presence of moisture among the package components can facilitate corrosion or oxidation and result in high levels of resistance, which can lead to electrical discontinuities or abnormal increases in forward voltage. Moisture and contaminants that enter and are trapped on the PCB and circuitry inside the LED driver and controls can cause corrosion and electrical malfunctions. When a battery comes in contact with water, corrosion of terminals, electrolyte leakage, overheating of the cell, fire and explosion can occur. Exposure to high condensing moisture may cause cloudiness of both the primary and secondary lenses in an LED flashlight.

Ingress protection (IP)

A waterproof LED flashlight is thoroughly sealed and gasketed at all points of entry, which include the integrated micro-USB charging port found on rechargeable flashlights, to exclude water, moisture, dust, contaminants and insects. The levels of sealing effectiveness of flashlights against intrusion from liquid and solid particles are identified by the Ingress Protection (IP) rating which is listed as ‘IP’ followed by two digits. The first digit indicates the level of protection against solid objects and the second digit relates to the level of protection against liquids. The higher the number the higher the level of protection.

Watertightness

Waterproof LED flashlights come with compete protection against the ingress of liquid (IP6X) but may vary in their ability to resist water ingress. IP65-rated flashlights provide an acceptable but not excellent protection against liquids. They are protected by water jets from any direction. For protection against strong water jets from any direction, the luminaire must be sealed to an IP66 rating. A number of outdoor applications require the flashlights to be protected against the effects of temporary immersion in water. An IP67-rated flashlight allows for up to 1 m of submersion for 30 minutes. For continuous immersion in water at a depth of greater than 1 meter, an IP68 rating is necessary.