My SQM-LE: Measuring the Night Sky's Quality

Level Up Your Dark Sky Monitoring: The SQM-LE & My DIY Enclosure

First off, I want to give a massive shout-out to Unihedron for generously providing me with two Sky Quality Meters: an SQM-L (the manual, lens-equipped model) and an SQM-LE (the Ethernet, lens-equipped model). And a huge thank you to Knightware for the fantastic SQM Reader Pro software!

For those unfamiliar, a Sky Quality Meter, as its name suggests, is a tool for measuring the quality of the night sky. The value it produces is in magnitudes per square arcsecond (mag/arcsec²). This essentially tells you the brightness of the sky background within a one-arcsecond square. The Ethernet version, the SQM-LE, allows for computer-based readings of this value. Now, I can monitor my sky quality remotely… What a luxury!

SQM-L : SQM-LE :

The SQM Reader Pro software is truly brilliant! It connects directly to the SQM-LE, extracts the instantaneous sky quality value, converts it into NELM (Naked Eye Limiting Magnitude), and automatically generates graphs. Super handy for tracking changes over time!

Since the SQM-LE isn’t inherently weatherproof, I needed to whip up an enclosure to protect it from the elements before installing it outdoors. After a quick raid of the plumbing aisle at my favorite hardware store, I had all the bits and pieces necessary to make my SQM-LE completely waterproof!

The ‘lid’ of the enclosure: The SQM-LE snug with a piece of insulation foam: The enclosure sealed up: