Sensor (for reptile UV lamp use) Silicon Carbide (SiC) Photodiode packaged on a gold-plated header via gold wire bonding under a UV glass window cap, hermetically sealed. Sensor (for outdoor sun only) Aluminum Galium Nitride (AIGaN) Photodiode with UG-11 filter and Teflon diffuser cap Radiometer Peak sunlight response bandwidth: 290-298 nm Total solar response: 290-400nm, Diffey Display: 3 ½ digit LCD Resolution: 0.1 UV Power Source: 9V DC battery Accuracy: ±10% ref NIST Proper usage of Solarmeter Ultraviolet Radiometer for Outdoor UV Index Measurement The instrumentation used to measure UV index for the U.S. E.P.A./NWS program is directed toward the sky in a global normal (perpendicular to level ground) inclination. Therefore, the Solarmeter Model 6.5 is designed to operate in the same fashion. Solar irradiance measured this way includes direct (reduced by the cosine law depending on solar zenith angle) plus diffuse (diffused by the atmosphere). This vertical (global) reading represents an average intensity value your body will experience while being active on a tennis or volleyball court, or lying flat on a blanket on the grass. If, however, you are reclined in a lounge chair facing the sun perpendicular to the sun angle, you will experience a higher UV intensity, as represented by pointing the Solarmeter directly at the sun. This value will typically exceed the actual UV index number. To obtain the UV index instantaneous value, the following instructions will provide the most consistent, accurate results: Stand clear of buildings, trees, etc. to obtain a "full sky" field of view. Hold the meter vertically out in front of your body. Press and hold the button on the front of the meter case. Note the reading on the LCD. This value represents the instantaneous UV index. The highest UVI values typically occur when the sky is a deep blue colour, and sometimes when the sun is between scattered white "puffy" clouds. Take extra precaution under these conditions to reduce sunburn potential. Note that various cloud and haze conditions reduce the UV index. When partly cloudy, take readings often and average clear with cloudy readings to correlate with actual UV index. Take care in hazy or slightly overcast conditions because although the direct UV reads less than when the sky is clear, the diffuse UV can be higher... as seen by pointing the meter in various directions. Among the outdoor variables affecting UV intensity are: Seasonality/Sun Zenith Angle Location/Latitude/Geography Reflective Surroundings Altitude Weather conditions Ozone Layer Thickness By regularly using the Solarmeter, you will become very informed of damaging UV levels in many and varied conditions. This knowledge, along with following the outdoor precautions mentioned above, should help enable you to avoid sun damage. Note: Battery operation voltage is 9V down to 6.5V. Below 6.5V, the LCD numbers will begin to dim, indicating the need for battery replacement. Under typical service load, the battery should last about 2 years.
