The Apogee SU-200 UV-A sensor measures ultraviolet-A radiation from 300-400 nm for monitoring supplemental UV and verifying lamp output. Choose the output for your system.All versions share the same UV-A detector and self-cleaning domed head; only the output differs.Available Options Unamplified analog (SU-200-SS) 0-2.5 V amplified output (SU-202-SS) 0-5 V amplified output (SU-205-SS) USB smart sensor (SU-220) SDI-12 digital output (SU-221-SS) Key Features UV-A spectral range 300-400 nm Photon-flux and energy-flux calibration factors Self-cleaning domed head, fully potted NIST-traceable, 4-year warranty Made in the USA and backed by Apogee's industry-leading warranty and support. Ideal Applications Supplemental UV-A monitoring UV lamp output verification Greenhouse and research UV tracking