Series 250-AF Inclined Manometer Air Filter Gauge

Brand: Dwyer Instruments, LLC

Dwyer® Durablock® Series 250-AF Inclined Manometer Air Filter Gauges are precision machined 1" thick solid acrylic plastic, virtually unbreakable and free of distortion.

The fluid bore is precision drilled to ±0.0002" 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 meniscus 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.

Gauges are suitable for use in ambient temperatures of -20 to 150° F. Connection fittings are positively sealed but easily removed for zeroing or addition of fluid.

Economy Model 452-AF is similar to the 250 Series except they are not equipped with over pressure traps. Two A-324 1/4" 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.
  • High-accuracy and easy to use make it a dependable device for many years of service
  • Easy to read polished inclined scale allows pressure minute pressure differences to be read
  • No moving parts mean no calibration or nothing to wear out



  • ± 1 % of Full Scale

Ambient Temperature Range

  • -29° to 66° C (-20° to 150° F)

Enclosure, Body Material

  • Arcrylic Plastic


  • Scale: 5-1/2”
  • Scale: 8”

NPT Connection

  • 1/8” NPT

Pipe Connection

  • 1/8” Pipe (DN 6)

Pressure Range

  • Inches WC: -0.20 to 2

Tube Connection

  • 1/4” Tube

  • Air Filter Gauge
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