Sky Quality Meter
SQM-LU-DL - Unihedron (Unihedron)
A USB enabled data-logging light meter for night-time sky brightness monitoring! An affordable meter for continual, connected or autonomous data-logging to measure sky brightness for astronomers and light pollution investigators. The "Sky Quality Meter - LU-DL" (SQM-LU-DL) measures the brightness of the night sky in magnitudes per square arcsecond.