General Tools & Instruments UV254SD UVC and UVA Data Logging Meter with Excel plus Formatted SD CardAccurately measures UVA and UVC light intensity; full scale auto ranges are 2 maw cm2 and 20 maw cm2 Measurement range is 240 nm to 390 nm and measurement accuracy is + 4% of full scale reading + 2 digits Performs real time automatic data logging at sampling time settable from 1 sec to 1 hr.; supports manual logging and changing of card storage location Comes with 2 GB SD memory card but works with cards up to 16 GB Features minimum maximum and data