Sheet #607u – ATR 0 – 1 – 2 – 3 function
Version 1.04a  User guide ATEQ 6th series Page 2/6 
1.2. ATR1 
The value of the transient is unknown. A special learning cycle must be carried out.  
The learning cycle for this function must be carried out 
on a known good part.
The instrument performs a normal test cycle and 
considers that the pressure variation measured at the 
end of the cycle is the transient. This value is saved and 
subtracted from the final result of subsequent tests. Its 
value is recalculated at each measurement cycle. 
Reasoning
: the part is a good part therefore the 
pressure drop measured is the transient. 
Fill       Stab      Test     Dump 
Time
Pressure
'P = Transient
Associated parameters to be set:
¾Start (Initial value of the transient),
¾Transient (actual, non modifiable value of the transient),
¾Per
centage drift (Percent of the reject level, the measurements used for transcient
calculation are less than this value).
¾Drift (Drift tolerance on acquisition of the transient, as a % of the Reject level).
1.3. ATR 2
The value of the transient is 
not known but the possible 
leak of the part is taken into 
account when the transient 
value is computed during the 
special cycle. 
Fill         Stab         Test1      Wait time 5 x test time      Test2  Dump
Time
Pressure
'P 1
'P 2 
At the end of test time 1, the ATEQ saves the pressure variation 'P1, function of the transient 
and the leak if there is one. 
'P1 = Leak + Transient 
Following the waiting time (equivalent to 5 times the normal test time), we consider that the 
transient phenomena has disappeared. During the second test time, the ATEQ instrument 
measures a second pressure drop 'P2 which corresponds to the leak. 
'P2 = Leak 
By taking these two pressure variations, we can calculate the transient. 
'P1 - 'P2 = (Leak + Transient) - Leak = Transient 
It is this transient which will be subtracted from the leak measurement of the following cycles. 
Through the use of the ATR, the ATEQ instrument is able to differentiate a Pass part from a Fail 
part without being influenced by the transient effects whilst keeping a short stabilization time.