Spark reduction goes hand in hand with good housekeeping

They may look like flashes of light, quickly here then gone, but sparks are actually bits of very hot metal.

A Sentry Air System spark reducer in the capture hood of a flexible extraction arm.

Our screen-and-mesh spark reducer, shown fitted into the capture hood of a flexible extraction arm, can be cleaned with pressurized air.

One reason we know this is the work of early researcher Robert Hooke. In this case, early means 17th century.

(More info about Hooke at the end of this post.)

Spark reducers can trap or break up the tiny metal bits, causing them to cool.

When cool, the resulting particles can be treated like any other form of industrial by-product — a target of good housekeeping practices.

We offer spark reducers for light grinding applications

Spark reducers are available for our Model 500/550 Series, Model 400/450 Series, and for the Model 300 Roundaire. They are frequently purchased for light grinding applications.

Three Sentry Air Systems fume extractors.

Check the table below to match extraction arms to model.

Table that relates Sentry Air fume extractors to extraction arm diameters.

The reducers’ combination of screen and mesh effectively reduces sparks.

The spark reducers fit snugly into the capture hoods, but they can be removed for cleaning with mild detergent.

Our spark reducers can also be cleaned with pressurized air while they remain in the hoods.

Contact us

If you’re looking for a fume extraction solution for your light grinding application, call us at 800.799.4609. You can also email our applications specialists at or contact them via the feedback form below and on the pages of our website.


Robert Hooke

Three versions of Robert Hooke plus one of his drawings of sparks.

Unfortunately for Robert Hooke and those of us who might like to know him better, no portrait of him has been uncovered; hence, the varied interpretations of his appearance.

There is gossip, however. Read about Isaac Newton’s possible role in The Royal Society’s blog Hooke, Newton and the ‘missing’ portrait


Trying to fit 26 hours into a 24-hour day? Consider a Quick Change Pre-Filter.

When multiple projects are happening at once and deadlines are approaching, the last thing you want to do is stop the flow of production to change the pre-filters on your air purification systems.

If you need a fast and easy solution, consider upgrading your unit with a Sentry Air Systems (SAS) Quick Change Pre-Filter (QCPF).

A QCPF is an optional accessory that allows simple and direct access to the pre-filter chamber; making it five times faster to change pre-filters than on a standard unit*.

The Importance of Pre-Filters

At SAS we offer three main types of pre-filters:

Filter Type
MERV Rating
MERV 11 11
Pre-Filter Pad (PFP) 8
Carbon Pre-Filter Pad (CFP) 7

When changed regularly, pre-filters protect and extend the life of the main filter by capturing large particulates.

Pre-filter pads are especially useful for welding, grinding, powder filling, spraying, and heavy particulate applications.

For moderate to heavy users, a pre-filter pad may need to be changed as often as once a week depending on hours of usage. SAS Technical Sales Representatives are able to assist with appropriate preventative maintenance schedules.

Changing a Pre-Filter

Pre-filters are very important to the overall functionality and longevity of a Sentry air purifier.

But in a high-production facility, replacing them may feel time-consuming even if only 10 minutes are required.

Close up of the Quick Change Pre-Filter shown on a Model 300 air cleaner.

Low Cost Upgrade. High Value Results.

Priced at $136 the QCPF makes changing a pre-filter five times faster than on a standard unit*, and eliminates the hassle of removing and re-inserting the main filters.

A QCPF is available on any Sentry Model 300, 400/450 and includes two clamps, a cover and pre-filter chassis insert, which can either come installed on a new unit or a user can retro-fit it to an existing unit.

By opening the clamps and removing the cover the user is able to bypass the main filters and gain direct access to the pre-filter — resulting in less hassle, easy maintenance and greater efficiency.

Contact Us

For more information on our Quick Change Pre-Filter or to order Replacement Filters, give us a call at 1.800.799.4609, email us at, or fill out this online form to have a Sentry Air Systems Applications Specialist contact you.

*Based on internal testing