ATEQ F620 - The Different Tests; Leak Test

Sheet #673u – Definition, characteristics and measurement principles
Version 1.04a User guide ATEQ 6th series Page 2/7
3. THE DIFFERENT TESTS
3.1. LEAK TEST
The leak test is most suitable for measuring small leaks (pressure drop). The following formula
is used to convert a leak expressed in units of flow to a drop in pressure:
)(cm V x0,0006
/min)(cmF
(Pa/s)P
3
3
'
F(cm
3
/min) = leak flow
V (cm
3
) = volume of the test part
'P (Pa/s) = pressure drop
Example:
Part which has dP/dt = 50 Pa/s Part which has dP/dt = 1 Pa/s
Test
1 s
2 s
3 s
.
.
n s
Pa/s
50
50
50
.
.
50
Pa
50
100
150
.
.
nx50
Test
1 s
2 s
3 s
.
.
n s
Pa/s
1
1
1
.
.
1
Pa
1
2
3
.
.
n
The choice of working in Pa or in Pa/s depends on the application.
In all events, it must not be forgotten that the range of the sensor in Pa or Pa/s is limited to 50,
500 or 5000 Pa depending on the instrument configuration.
3.1.1. The main types of measurement
There are three measurement methods:
¾ Direct measurement,
¾ Indirect measurement,
¾ Sealed component measurement.
These three principles concern measurements carried out under pressure and under vacuum.
The configuration is determined by the application, and must be determined before ordering the
instrument.