Whether you’re applying a finish to an old rod you’re restoring, or spraying some poly on a newly-built cocobolo desk, humidity in your air lines is a huge liability; it can ruin and otherwise flawless execution. Like a pregnancy test for your compressor, DeVilbiss’s humidity indicator changes color to indicate the presence of moisture — so you can take action before attempting a one-chance-only finishing process.
It installs in-line, so you can check it at a glance without digging out a tool.
The colored indicator beads in the device begin to change from blue to pinkish clear at 10% humidity, and they turn completely pinkish clear by 15% humidity. The beads can change color numerous times before you need to replace the unit.
At $24, it’s a small price to pay for peace of mind. And the time and aggravation you save could be your own.