HELLING is a specialist in designing and manufacturing LED lights equipped with UV-A LED, white light LED and also blue light LED. UV-A LED lights are used in penetrant and magnetic particle testing with fluorescent test medium.

The increasing lifetime of the UV LED has contributed to today's widespread acceptance in surface inspection with fluorescent detection media (penetrant and magnetic particle testing). This also applies to the aviation industry sector.

LED manufacturers now guarantee a constant output intensity for a period of approximately 10,000 operating hours. UV LED area lights can be switched on and off as needed and without delay. They do not require any warm-up time and do not have to be in operation permanently. This further reduces the low energy consumption and increases the service life and service life expectancy accordingly.

Inhomogeneity made visible under UV irradiation during the indentation test with fluorescent test agent.

Magnetic particle testing with fluorescent test medium: under UV irradiation, the crack indications are clearly visible.

The main advantages of the UV-A LED lamp compared to the conventional high-pressure mercury lamps used in the past are

• Significantly longer operation life
• Lower energy consumption
• Immediate operational readiness after switching on

HELLING UV-Inspector 150 hand lamp for use in penetrant testing and magnetic particle testing

Meanwhile, HELLING offers various designs of UV-A LED lamps:

• Stationary lamps in modular design
• Hand lamps with battery or mains operation
• Compact, handy pocket lamps
• Lamps with controll functions
• Lamps for specific industrial sectors (aviation, automotive, ...)

UV radiation

UV radiation (ultraviolet radiation) is electromagnetic radiation invisible to the human eye with a wavelength of 100 nm to 380 nm. This range is divided into UV-A (380 - 315 nm), UV-B (315 - 280 nm) and UV-C (280 - 100 nm)(DIN 5031).

UV radiation is used in various industrial applications due to its high radiation intensity, e.g. for curing films, plastics, paints and varnishes. In NDT, the excitation of fluorescent materials in the visible spectral range is mainly used (penetrant and magnetic particle testing).

As UV radiation can damage the human eye and skin, the limit values for permissible radiation must be observed (see UVV). Also, UV protective goggles should always be worn!

HELLING also limits the UV radiation of its lamps with appropriate filters. All UV-A lamps are subject to careful quality control.

Spectral distribution of an A source

A certificate for the analysis of the spectral irradiance can be issued at the customer's request. This is carried out in the in-house measurement laboratory.