Axis

Permeance & diffusivity

perm (US)perm

The US vapour permeance unit: grains per ft² per hour per inHg.

Dimension
T³·I²/L⁻²·M
Canonical signature
L^-2*M^-1*T^3*I^2
System
us customary
Exactness
Approximate

Definition record

How this unit is defined

Canonical base
1 perm = 5.72135e-11 S
Conversion type
linear
Historical notes
1 perm ≈ 5.72 × 10⁻¹¹ kg/(Pa·s·m²).
Aliases
US perm, perms

Same dimension

Related units

siemenssiSquettasiemenssiQSronnasiemenssiRSyottasiemenssiYSzettasiemenssiZSexasiemenssiESpetasiemenssiPSterasiemenssiTS

Common conversions

Every conversion routes through the canonical base of the dimension.

1 perm = 5.72135e-11 S

Approximate relationship

10 perm = 5.72135e-10 S

Approximate relationship