Pervaporation was initiated by applying vacuum on the permeate side, which was measured in a digital vacuometer
and controlled by a needle valve.
For the measurement of maximal inspiratory pressure (MIP) and TIE index we used a prototype of a digital vacuometer
called MagnaTIE (Magnamed, Sao Paulo, SP, Brazil), with a scale of 300 cm[H.sub.2]O and an increment of 0.1 cm[H.sub.2]O and a time interval of 100 ms for each pressure.
In the final product, the vacuum maintenance is evaluated in the package through perforation of the top by a vacuometer
The vacuum system consists of a vacuum chamber and a vacuum installation post UVN-74P3, oil vapor diffusion pump NP-400, vacuum pump AVZ-20, vacuometers
VIT-3 and VMB-8, vacuum sensors (thermocouple TP-1, ionization IP-1, magnetic blocking M-2) located in the vacuum volume.