Dwyer Instruments A-350 Aspirator Bulb

If you're out in the field running leak checking tests or validating pressure switch calibration, the Dwyer A-350 Aspirator Bulb is a staple in the technician’s bag. This manual pump is engineered to provide a reliable source of positive pressure or vacuum for various HVAC test instruments. By simply connecting your 1/4 inch tubing to the barbed fitting, you can generate the required pressure with a single hand. For vacuum applications, such as pulling samples into a CO2 indicator or stack analysis tool, simply deflate the bulb before making your connection to draw air or smoke directly into the gage. Its compact, handheld design makes it an ideal companion for magnehelic gauge calibration and general maintenance where portable, non-electric pressure sourcing is required. Built for the rigors of mechanical rooms and industrial environments, the A-350 ensures high repeatability for sensitive pressure transmitter calibration and diagnostic workflows.

• Dual-Function Capability: Easily switches between generating positive pressure and vacuum sourcing based on connection timing.
• Enhanced Compatibility: Features a standard 1/4 inch barbed process connection, fitting most HVAC/R diagnostic tubing.
• Field-Ready Design: Lightweight and portable construction allows for one-handed operation in tight mechanical spaces.
• Cost-Effective Calibration: A high-performance manual alternative to expensive electronic pumps for smoke leak testing.
• Proven Reliability: Seamlessly integrates with the Magnehelic 2010 series and other analog gauges for accurate zeroing and spanning.

How do I change from pressure to vacuum mode?
To source pressure, connect the tubing first and then squeeze the bulb. To source a vacuum, squeeze the bulb fully, then attach the tubing to your duct or stack probe to draw air back into the instrument.

What tubing size is best for the A-350?
The unit is designed with a 1/4 inch barbed fitting, which is the standard size for most Dwyer Instruments and HVACR diagnostic manometers and gauges.

Can this bulb be used for continuous monitoring?
No, this is a manual aspirator bulb designed for spot-checking, leak testing, and calibrating instruments. It is not intended for permanent or continuous pressure monitoring applications.

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Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.