R_1=\frac{\sqrt{\frac{M_a}{M}}\cdot <!--\; \cdot \; -->L\cdot <!--\; \cdot \; -->P_e}{P_o}\cdot <!--\; \cdot \; -->[1-<!--\; -\; -->e^{-<!--\; -\; -->\frac{\sqrt{\frac{M_a}{M}}\cdot <!--\; \cdot \; -->L}{P_o\cdot <!--\; \cdot \; -->V}\cdot <!--\; \cdot \; -->t_1}]\cdot <!--\; \cdot \; -->e^{-<!--\; -\; -->\frac{\sqrt{\frac{M_a}{M}}\cdot <!--\; \cdot \; -->L}{P_o\cdot <!--\; \cdot \; -->V}\cdot <!--\; \cdot \; -->t_2}

L : equivalent standard leak rate atm·cc/s mbar·l/s Pa·cm³/s atm·mol/s air helium nitrogen oxygen argon

V : internal volume of the device package cavity cc - cm³ mm³ µl

Pₑ : pressure of exposure atm psi bar absolute

t₁ : time of exposure to Pₑ s min h

t₂ : dwell time between release of pressure and leak detection s min h

Reverse Calculation

If R is measured at atm·cc/s mbar·l/s Pa·cm³/s atm·mol/s helium air nitrogen oxygen argon then L= atm·cc/s mbar·l/s Pa·cm³/s atm·mol/s air helium nitrogen oxygen argon

DISCLAIMER : Please contact Oneida Research Services, Inc. at (315) 736-5480 or Daniel Rossiter by email at djrossiter@orslabs.com for technical discussions regarding the application of the Howl-Mann equation.

30-sep-2016 v1.3