General Tools UV254SD UVC and UVA Data Logging Meter with Excel plus Formatted SD Card Accurately 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 hold, big (2.5 inch) front-panel Green backlit LCD and auto power off function