Inclined Manometer Air Filter Gages - Series-250

Model No. 250.5-AF

FEATURES Highly accurate and easy to use yet almost indestructible, Dwyer Series 250-AF Inclined Air Filter Gages are foolproof and dependable. There are no moving parts - no mechanical linkages - nothing to wear out, jam or deteriorate from vibration. They never need calibration. The mirror polished inclined scale allows the operator to easily read minute differences in differential pressure across the filter accurately without parallax error. The only servicing required is occasional zeroing. If cleaning is necessary, it is easily done with soap and water.

CONSTRUCTION Dwyer DURABLOCK® Series 250-AF Gages are precision machined 1" thick solid acrylic plastic, virtually unbreakable and free of distortion. The fluid bore is precision drilled to ±.0002" to assure life long accuracy. A glass spirit level is built into the body and encapsulated to prevent damage or tampering. The scale is mirror polished chrome plated brass to assure parallax free reading by alignment of the miniscus with its reflection. Safety traps are incorporated in the body to prevent loss of fluid due to pressure surges. Red and green signal flags indicate clearly when a filter change is necessary. Gages are suitable for use in ambient temperatures of -20° to +150°F. connection fittings are positively sealed by "O" rings but easily removed for zeroing or addition of fluid. Furnished complete with instructions.

Economy Model No. 451-AF

Economy Models 451-AF and 452-AF are similar to 250 Series except they are not equipped with over pressure traps. Two A324 ¼" compression fittings are included with each Gage but not shown, Bodies are of 5/8" thick acrylic and scales are mirror polished, epoxy coated aluminum. See image at left.

SUGGESTED SPECIFICATION for Architects and Engineers

An air filter gage for measuring the resistance to air flow through the filters shall be installed, one for each bank of filters. The gage shall be of inclined tube differential type (equipped with vent valves for zeroing) shall be of solid acrylic plastic construction with built-in level vial (and over pressure safety traps 250 Series only), shall have an adjustable mirror-polished scale, shall be furnished complete with two 5-foot lengths ¼" tubing, two static pressure tips, mounting hardware, additional bottle of red gage oil and instructions. Gage shall be Dwyer Instruments, Inc. Catalog No. ____, reading to __in. divisions.

OPERATING RANGES AVAILABLE AND DIMENSIONS

Model Number	Range: Water Column	Minor Div.	Scale Length Inclined Inches	Overall Size Inches
250-AF 250.5-AF 251-AF 252-AF 209-AF 260-AF 350-AF*	.10-0-1.0" .10-0-1.0" .05-0-.50" .20-0-2.0" .20-0-3.0" 0-1.5" 0-4"	.02" .01" .01" .02" .02" .02" .10"	5 ½ 8 5 ½ 8 8 5 ½ 4 ½*	8 ½ x 4 1/8 x 1 11 3/8 x 4 x 1 8 ¼ x 3 3/8 x 1 11 1/8 x 6 ½ x 1 11 ¼ x 6 7/8 x 1 8 3/8 x 5 7/8 x 1 3 x 8 ¼ x 1
451-AF 452-AF	0-1" 0-2"	.01" .02"	8 8	11 x 2 1/8 x 5/8 11 x 4 x 5/8
*Vertical Scale	2 PSI Maximum Working Pressure

STANDARD ACCESSORIES AND OPTIONS

Air Filter accessories in optional kit includes surface mounting bracket with screws, two static pressure tips with integral compression fittings, two five foot lengths of ¼" aluminum tubing and two molded Plastic vent valves. To order, specify No. A-609 Air Filter Kit.

A-310B (3 way vent valve)
A-317 (Plastic Gage plug)

Optional vent valves for easy zeroing of gage are available at extra cost. Two are required per gage.