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Running Men
4125 Market St #10
Ventura, CA 93003
(800) 235-3333
# 3420 & 3421 Spirometer (PFT) Filters

Adapters available for any spirometer or PFT system.

No. 3420 shown top left.
Both filters may be used for Spirometry, Pulmonary Function Testing & Exercise Stress Testing.

# 3420 is a low cost, highly efficient Pulmonary filter.
New # 3421 (green) is almost identical to 3420, but fits onto more spirometers.

Here is what you get:

Peace of Mind. Because Pulmoguard is the most efficient PFT filter on the market. It uses the most recent version of 3M's Filtrete as its filter media. Pleating the media has enabled this filter to maximize the effective filter surface area. Nelson Laboratories of Utah, the world's leading microbiological testing laboratory, has certified that the Pulmoguard is well over 99 percent efficient at stopping bacteria and viruses. This means you are providing the best protection from cross-contamination for your patients.

Unimpaired Accuracy. Pleating the filter media allows the Pulmoguard to have the lowest dead space of any high efficiency filter. Its dead space is 50 cc, which is far lower than recommended by the ATS for all lung testing.

Continued Adherence to ATS standards. Pulmoguard has very low flow resistance because the mathematically defined air deflectors and a truncated cone style housing effectively distribute the exhaled air uniformly across the entire filter area. This unique design results in an air resistance of only .438 cmH2O/L/sec, well below the value recommended by ATS and the lowest of any high efficiency filter. This is well below the ATS standard of 1.5cm H2O/L/second.

The 3420 filter can be used without any adapter on most Spirometers and Pulmonary Function Systems. Small end tapers from 26mm to 32mm OD, the large end tapers from 34mm to 36mm OD (30.5mm ID). It is bi-directional: meaning you can blow into either end with equal filtration efficiency.

10 Reasons Not to Use a Filter

  1. I only test healthy patients.
  2. I never had any cross-contamination problems before.
  3. My staff washes the mouthpiece or uses a disposable one.
  4. TB is only a problem in third world countries.
  5. AIDS cannot be contracted via pulmonary function tubing or valves.
  6. I can't charge my patient for this filter.
  7. The filter costs more than the time and material of disinfecting tubing,
    valves and mouthpieces.
  8. My malpractice insurance carrier is not going to reduce my premium
    if I use a filter.
  9. I don't know anyone else that uses a filter.
  10. I have no money in my budget for filters.

Mouthpieces for the 3420 Filter:

Our 1025 cardboard mouthpiece, the 1018-27 plastic mouthtube, and the 1001 reusable mouthpiece fit into the large end of the 3420.

Our Z102x-50 cardboard mouthpiece fits into the small end.

Mouthpieces for the 3421 Filter:

Our 1022 cardboard mouthpiece fits into the large end of the 3421 filter.

Our # 1000 reusable mouthpiece and our # 1018-27 plastic mouthtube fit over the small end of the 3421 filter.

3421 Dimensions (approximate):
Large end: 30 to 30.6mm OD taper. 26.5mm ID
Small end: 28.6 to 29.5mm OD taper. 25.5mm ID

VacuMed carries a large assortment of adapters, click on Adapters

Spirometer Filter with Adapter for Med-Graphics "preVent" Pneumotach

For Medical Graphics users that re-use the flow sensor.
Includes 50 each #3420 filters with attached coupler to fit the flow sensor with minimum dead space. Our # 1000 plastic re-usable mouthpiece fits on other end of filter.

Last Updated: 7 April 2022

Qty Product Catalog Number Price

"Pulmoguard" (blue) Spirometer Filter, Box of 50 3420 162.00
  Buy 4 or more for $152.00 each

Spirometer Filter with Adapter for "preVent" 3420MG 165.00
  Buy 5 or more for $152.00 each

"Pulmoguard" (green) Spirometer Filter, Box of 50 3421 162.00
  Buy 4 or more for $152.00 each

Cardboard Mouthpiece fits small end of 3420, box of 50 Z102X-50 12.50
  Buy 5 or more for $11.25 each

Plastic Mouthpiece fits large end of 3420, box of 100 1018-27 27.55
  Buy 5 or more for $24.85 each