When selecting the UV lamps it is important to know what features to look for in a lamp. A quality lamp will create the best illumination for the appropriate application when paired with fluorescent dye.
(1) Peak Wavelength
The most important consideration for a UV-A lamp is its peak wavelength. In former times, Mercury’s elemental emission line was used in the formulation of testing products and produces fluorescence under UV-A lighting at 365 nm. Therefore, an inspection lamp needs to achieve a peak wavelength between 360-370 nm.
If the lamp produces too wide or too focused beam for its specific application, results will be skewed and inconsistent. Always pay attention to the recommended working distance and select a lamp that produces the correct coverage for the part or component to be inspected. Furthermore, choose a lamp without hot-spots in the beam profile, as this can lead to a sort of ‘tunnel vision’ whereby irradiated areas outside of the focus area are not inspected properly.
For portable, handheld lamps, power supply is a critical concern since the device’s LED intensity will diminish proportional to the voltage and current. Requirements stipulate that 1,000 μW/cm2 is the bare minimum intensity, so ensure that your desired lamp is capable of exceeding this minimum intensity during daily use.
Requirements and tolerances for NDT with UV-A lamps depends on the industry and the application, and a quality lamp should meet international standards for NDT methods. Industries such as aerospace manufacturing have much higher standards, so they’ve produced requirements for UV-A testing with ASTM E3022. A product that meet this standard will naturally get nearly any job done to this high standard.
Post time: Sep-27-2021