In the shop: Monitoring dust levels
January 5, 2011 | 6:00 pm CST

Efficient dust collection systems are a joy to operate, whisking away all those chips and sawdust out of sight. But that’s the problem – everything is out of sight. With standard opaque collection drums, it’s not easy to tell when it’s time to empty the container. Sometimes that leads to annoying results such as the chips backing up and clogging a cyclone collector. Oneida Air Systems has come up with an ingenious solution to that problem in the form of their Dust Sentry sensor system.

Infrared magic 

The Dust Sentry uses an adjustable low-voltage infrared sensor and strobe system to provide an effective alert even in a noisy woodworking operation. The sensor detects when the dust and chips reach a specific level in the container. That sets off a strobe light to warn you it’s time to empty the drum.

Comprised of three basic parts, the system is easy to use and install on most any existing dust collection container. There is the sensor, which requires a ¾-inch mounting hole. That is connected to the strobe light, which can be mounted remotely from the collector. Finally, it is all connected to a small 110-volt transformer to provide power to the system.

Easy installation 

We tried the system on a couple of challenging applications. One was the plastic lid of the Oneida Dust Deputy mini-cyclone system, which uses a 5-gallon plastic bucket as the dust receptacle. The other was a shop-built dust collection system with a wooden pullout drawer. In both of these applications, the sensor was able to consistently warn of the dust level. The only adjustment was using a small screwdriver on the level set screw, which was easy to do using a hand to trigger the unit.

At first, the strobe light going off was a little startling, but once we remembered what it meant, we were off to dump the collector. The only issue I could see is in the occasional shop that also uses a strobe alert for telephone calls, but I’m sure it would be easy to keep the two strobes straight by location.

For more information about the system, visit

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About the author
William Sampson

William Sampson is a lifelong woodworker, and he has been an advocate for small-scale entrepreneurs and lean manufacturing since the 1980s. He was the editor of Fine Woodworking magazine in the early 1990s and founded WoodshopBusiness magazine, which he eventually sold and merged with CabinetMaker magazine. He helped found the Cabinet Makers Association in 1998 and was its first executive director. Today, as editorial director of Woodworking Network and FDMC magazine he has more than 20 years experience covering the professional woodworking industry. His popular "In the Shop" tool reviews and videos appear monthly in FDMC.