Convert Gurley Seconds to Frazier (cfm/ft²)
Gurley Seconds and Frazier (cfm/ft² at 125 Pa) are inversely related: cfm/ft² @125 Pa = 3.126991894 ÷ s/100 mL, so 1 s/100 mL = 3.126991894 cfm/ft² @125 Pa.
Also searched as Gurley to Frazier, Gurley seconds to cfm/ft2 and Gurley to air permeability cfm.
1 s/100 mL = 3.126991894 cfm/ft² @125 Pa
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk Gurley second to Frazier converter to paste a column from Excel.
How to Convert Gurley Second to Frazier (cfm/ft²)
- cfm/ft² @125 Pa = 3.126991894 ÷ s/100 mL
- s/100 mL = 3.126991894 ÷ cfm/ft² @125 Pa
- Example: convert 1 s/100 mL to cfm/ft² @125 Pa: 3.126991894 ÷ 1 = 3.126991894 cfm/ft² @125 Pa
Reference conditions. s/100 mL: 100 mL through 6.45 cm² (1 in²) at 1.22 kPa (TAPPI T 460, ISO 5636-5); assumes air flow proportional to pressure difference. cfm/ft² @125 Pa: Measured at 125 Pa (0.5 inH₂O) as in ASTM D737; assumes flow proportional to pressure difference.
Formula
cfm/ft² @125 Pa = 3.126991893836 ÷ s/100 mL
Derivation from SI units:
- Gurley t = seconds for 100 mL of air through 6.45 cm² at 1.22 kPa, so P = 100 mL ÷ (6.45 cm² × 1.22 kPa × t) ≈ 127.08 ÷ t µm/(Pa·s).
- 1 cfm/ft² = 0.00508 m/s; at 125 Pa that is 0.00508 ÷ 125 = 4.064 × 10⁻⁵ m/(Pa·s) = 40.64 µm/(Pa·s).
- Solving for cfm/ft² @125 Pa: cfm/ft² @125 Pa = 3.126991893836 ÷ s/100 mL (a higher s/100 mL means a lower cfm/ft² @125 Pa)
One unit is a measured value, so the factor is approximate. Gurley Second definition: Gurley second; Frazier (cfm/ft²) definition: Frazier (cfm/ft² at 125 Pa).
Worked examples
- A nonwoven of 1 s/100 mL is about 3.126991894 cfm/ft² @125 Pa.
3.126991894 ÷ 1 = 3.126991894 cfm/ft² @125 Pa - A paper of 20 s/100 mL is about 0.1563495947 cfm/ft² @125 Pa.
3.126991894 ÷ 20 = 0.1563495947 cfm/ft² @125 Pa
Gurley Second to Frazier (cfm/ft²) conversion table
| Gurley Seconds (s/100 mL) | Frazier (cfm/ft²) (cfm/ft² @125 Pa) |
|---|---|
| 1 s/100 mL | 3.126991894 cfm/ft² @125 Pa |
| 5 s/100 mL | 0.6253983788 cfm/ft² @125 Pa |
| 10 s/100 mL | 0.3126991894 cfm/ft² @125 Pa |
| 20 s/100 mL | 0.1563495947 cfm/ft² @125 Pa |
| 30 s/100 mL | 0.1042330631 cfm/ft² @125 Pa |
| 50 s/100 mL | 0.06253983788 cfm/ft² @125 Pa |
| 100 s/100 mL | 0.03126991894 cfm/ft² @125 Pa |
| 200 s/100 mL | 0.01563495947 cfm/ft² @125 Pa |
| 500 s/100 mL | 0.006253983788 cfm/ft² @125 Pa |
| 1000 s/100 mL | 0.003126991894 cfm/ft² @125 Pa |
Where it's used
Gurley results are converted to Frazier cfm/ft² (ASTM D737 at 125 Pa) to compare papers and membranes with fabrics and filter media. Frazier ≈ 3.127 ÷ Gurley seconds, assuming flow proportional to pressure.
Gurley Second to other air permeance units
| Conversion | 1 s/100 mL equals |
|---|---|
| Gurley second to Frazier | 3.126991894 cfm/ft² @125 Pa |
| Gurley second to micrometre per pascal second | 127.0809506 µm/(Pa·s) |
| Gurley second to Bendtsen | 11208.53984 mL/min (Bendtsen) |
| Gurley second to millimetre per second at 100 Pa | 12.70809506 mm/s @100 Pa |
| Gurley second to millimetre per second at 200 Pa | 25.41619011 mm/s @200 Pa |
Frequently asked questions
How do I convert Gurley to Frazier?
Frazier ≈ 3.127 ÷ Gurley (100 mL). So 1 s ≈ 3.126991894 cfm/ft² @125 Pa.
Why is the conversion approximate?
Gurley runs at 1.22 kPa and Frazier at 125 Pa; the formula assumes laminar flow, where flow is proportional to pressure. Very open fabrics deviate.
What is the formula for Gurley seconds to Frazier (cfm/ft² at 125 Pa)?
cfm/ft² @125 Pa = 3.126991894 ÷ s/100 mL. The two systems are inversely related, so divide the constant by the value; do not multiply. For example, 3.126991894 ÷ 1 = 3.126991894 cfm/ft² @125 Pa.
Why does a higher s/100 mL give a lower cfm/ft² @125 Pa?
Gurley Seconds counts length per unit mass (an indirect system), while Frazier (cfm/ft² at 125 Pa) counts mass per unit length (a direct system). A finer yarn has a higher indirect number and a lower direct number.
Is the s/100 mL to cfm/ft² @125 Pa conversion exact?
Not exactly. The Gurley second is a measured value (100 mL through 6.45 cm² (1 in²) at 1.22 kPa (TAPPI T 460, ISO 5636-5); assumes air flow proportional to pressure difference.). The Frazier (cfm/ft² at 125 Pa) is a measured value (Measured at 125 Pa (0.5 inH₂O) as in ASTM D737; assumes flow proportional to pressure difference.). Results are good to about 5 significant figures.
Sources
- ISO 5636 Paper and board — Determination of air permeance (Part 3: Bendtsen method; Part 5: Gurley method), International Organization for Standardization , Part 5, Gurley method.
- TAPPI T 460 om-21 Air resistance of paper (Gurley method), TAPPI .
- ASTM D737 Standard Test Method for Air Permeability of Textile Fabrics, ASTM International .
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert Gurley Seconds to Frazier (cfm/ft²). Retrieved October 29, 2026, from https://scientificconverters.com/air-permeance/gurley-seconds-to-frazier/
IEEE
Scientific Converters, "Convert Gurley Seconds to Frazier (cfm/ft²)," scientificconverters.com. Accessed: Oct. 29, 2026. [Online]. Available: https://scientificconverters.com/air-permeance/gurley-seconds-to-frazier/