How to choose a UV Detector

The major application is UV lamp monitoring.  Other applications include flame sensing and sensing of sunlight dose to monitor tanning and avoid sunburn.

UV Lamp monitoring

Silicon carbide is the detector of choice when monitoring UV lamps in germicidal or other high power applications (usually mercury lamps are used).   There are several reasons for this. 

First of all, SiC photodiodes do not degrade ("age") significantly under high does of UV-C light.  On the other hand, other sensors (such as silicon photodiodes) degrade quickly.  Click here for aging data on various sensors under high UV-C exposure. 

Secondly, the intrinsic lack of visible and near infrared photo-response of SiC means that for most applications, no optical filter is required to suppress response to visible and near-IR.  Contrast this with silicon, which is several times more sensitive in the visible and near-IR than it is in the visible.  With silicon the optical filter required to reduce or eliminate response to these unwanted longer wavelengths would COST much more than the sensor itself.  On the other hand, in those instances where no or minimal response to UV-B or UV-A can be allowed, SiC can be paired with an inexpensive and durable filter since the filter only needs to suppress wavelengths shorter than about 420 nm (compared to less than 1100 nm for silicon)!

SiC is the clear winner for UV lamp monitoring.

Tanning and Sunburn monitoring

The question for this application is: how accurate do you need to be?  (In general the expected does is not so high that the sensor is expected to degrade due to exposure to the radiation.

For low cost applications the EryCA TiO2 device is recommended.

For higher accuracy (at higher cost) choose the EryF*.

Flame sensing

The magic wavelength for flame sensing is 310 nm (details here), where the OH band is bright in flame.  However, unless the sensor is in a position where no room light and no sun light can fall on it, 310 nm flame sensing will produce false alarms.  In addition, flames are not really very bright, even at 310 nm, so the larger (and more expensive) active area solid state sensors are required.  Nevertheless at least one gas turbine flame sensor based on SiC photodiodes is in production.

The leading product for this application is the Geiger Mueller tube, a sort of solar blind single photon counter that can sense a lighted match at 15 feet.

We recommend and offer the GM tube for this application in most instances.  Click here for details.

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