To be sure that custom earpieces for hearing protection show optimal behaviour one can perform a fast leak test.
A proper test provides certainty about a perfect fit of the earpiece. When there is a perfect fit, noise can only enter the ear canal through the noise filter and not outside to the earpiece.
For that purpose the room in the ear canal, between eardrum and otoplastic, is brought to a small overpressure of 5mB (0,073psi), by means of air. When the pressure is reached, the air system is closed and when the pressure stays stable for five seconds the otoplastic has the perfect fit. The related software controls the earpiece tester and allows the user to analyze the pressure course, real time, by means of a graph.

Test pressure : 5mB (≡ 51mmH2O or 500Pa)
Trip pressure : < 4mB
Test time : 5 seconds
Test duration : max. 10 seconds
USB : version 2.0 + 3.0