Labconco Precise Controlled Atmosphere and Basic Glove Boxes 5220131 - Manual (Page 27)

Chapter 3: Getting Started
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Pressure Change Leak Testing Method Summary
(ISO-10648-2)
The method consists of measuring the pressure rise per unit time after
establishing a negative pressure in the main chamber of the glove box. Use
-1000 Pa for the acceptance test and -250 Pa for the operational test. The
hourly leak rate includes adjustments for barometric pressure and temperature
changes which can be calculated as T
f
:
T
f
= (60/t) * ((PnT
1
/P
1
Tn) -1) where
t is the duration of the test in minutes.
P
1
is the absolute pressure (ambient barometric pressure minus under
pressure) at the first reading in Pascals.
Pn is the absolute pressure (ambient barometric pressure minus under
pressure) at the last reading in Pascals.
T
1
is the temperature at the first reading in Kelvin.
Tn is the temperature at the last reading in Kelvin.
60 represents 60 minutes in an hour.
T in Kelvin is equal to degrees Celsius + 273.