Spot Extractor for Lab Furniture

Quick Answer: The Spot Extractor for Lab Furniture is an articulated spot extractor arm, also called a snorkel or local exhaust arm, that is mounted on or above a laboratory bench and ducted to an exhaust fan, so its hood can be brought close to a small source of fumes, odours or dust and draw them away before they reach the user’s breathing zone.

Capturing Fumes at the Source

A fume cupboard encloses the work; a spot extractor does not. Instead, the hood at the end of the arm is brought close to the source, for example a soldering iron, a dish of fixative, a small evaporation or an instrument exhaust, and the air flowing into it carries the contaminant away. The jointed arm lets the user swing and angle the hood as the work moves, and friction or tension joints hold it where it is set.

Capture only works near the hood. Air speed in front of an extraction opening falls off very quickly with distance, so a common rule of thumb is to keep the hood within about one hood diameter of the source. Placed further away, the extractor mostly pulls in clean room air while the fumes drift past. For that reason a spot extractor suits small, low-hazard releases; volatile toxic chemicals, heating of acids and anything that could reach a hazardous concentration belong in a fume cupboard.

On lab furniture the arm is fixed to a bench, service spine, wall or ceiling with a bracket for spot extractor and ducted to a fan. When several arms share one fan, a damper in each branch balances the airflow between them.

Specifications

Using and Maintaining the Arm

• Reposition the hood each time the work moves; the arm only works when it is close.
• Check that the fan is running before starting, for example by holding a tissue strip at the hood.
• Tighten joints that have slackened so the arm does not drift away from the source.
• Clean the hood and the first section of the arm regularly, as condensate and dust build up there.

Applications

• Soldering and electronics benches in physics and engineering labs.
• Tissue processing and staining stations that release small amounts of fixative vapour.
• Venting instrument exhausts, such as small ovens or analyser outlets.
• Weighing or mixing powders at a bench, where light dust needs capture.

Why Choose LabEquip

Histology labs, electronics workshops and teaching labs adding local exhaust to existing benches are the usual buyers of spot extractors. LabEquip lists the arm and its mounting bracket in General Lab Products; for ducting and fan matching, describe the bench layout through our contact page.

Frequently Asked Questions

How is a spot extractor different from a fume hood?

A fume hood encloses the work behind a sash and draws air through the enclosure. A spot extractor is an open hood on a movable arm that captures fumes near their source; it is simpler to install but gives far less protection for hazardous work.

How close to the source should the hood be?

As close as the task allows, typically within about one hood diameter. The capture effect falls sharply with distance, so a hood set well back from the fumes does little.

Can the arm be fitted to existing lab benches?

Yes, that is its main purpose. It is fixed with a bracket to the bench, wall or ceiling and connected by duct to an exhaust fan, which may already serve other extraction points in the room.

Does a spot extractor need its own fan?

It needs a fan somewhere in its duct run. Several arms can share one fan through a common duct, with a damper at each branch to balance the airflow between them.

What work should not be done under a spot extractor?

Work with volatile toxic or carcinogenic chemicals, strong acid fumes, or anything that could release a hazardous amount of vapour should be done in a fume cupboard. The spot extractor is meant for small, low-hazard releases.

How should the arm be maintained?

Check the joints periodically and tighten them if the arm drifts, clean the hood and the first duct section where residue collects, and check the airflow at the hood from time to time with a simple smoke or tissue test.

Last Updated: September 2026