There are many
different types and as many different qualities of UV
Blacklight units on the market. Generally speaking they fall
into two types; UV Fluorescent Tube or UV LED based units.
exception of cheap, sub-standard units, fluorescent tube
based blacklights are generally consistent in the quality of
UV light emitted. However the vast majority of UV LED based
blacklights (torches) being sold today are very poor quality
units barely able to come close to emitting the required
frequency of light.
of a UV lighting unit is too produce Zero Visible Light with
100% 365nm UV Output. This not yet possible (or
affordable) but let price be your guide to how close your
choice of UV light will come to this.
The more visible light you see, the worse the UV
quality will be.
applications a certain amount of visible UV glare is
acceptable which makes the basic UV units affordable.
We have come
up with a very simply way of checking the frequency range (UV Quality) of UV LED Torches. The images below
clearly show how the quality of light varies between the
different classes of Torch.
look identical on the screen but performance and quality can
UV Blacklights come in 3 Main Frequency Ranges:
Range: 390 - 405nm)
operating in the wider 390nm - 405nm range generally use
poor quality 'cheap' UV LEDs which produce far too much
unwanted visible 'purple glare' and far too little in the
way of a useful UV light.
TIP: A general
rule-of-thumb is; the more LEDs the torch has, the lower the
Quality of UV produced. Avoid torches with more than 9
Range: 380 - 385nm)
UV Torches outputting in
the 380nm range perform much better and produce far superior
results, with a much reduced 'visible' output. Such units
will naturally be more expensive than the cheaper 39-405nm
UV Forensic Torch belongs to this class.
Range: 365 - 375nm)
contrast, the higher quality, more expensive torches
producing the 365nm wavelength, produce a near pure UV
output which is the optimum frequency for UV fluorescence.
This means you will see far more detail and in a greater
range of colours than any other wavelength.
Both the Wash
Checkpoint Lamp and
UV Handheld Lamp belong to this class.
below uses Invisible UV GERM Powders which require UV light
to show their 'glow' colour. The powders are a neutral white
colour whilst in ordinary light. Move your mouse over
an image to see the normal colour.
As you can
see, the best colour generation and brightness comes from
the 365 - 375nm Frequency of UV Light.