SUPPLEMENT MASTERLESS Q&A
Q1 : How is Fitting testing different from Mastering testing?
A1: When a variety of works are tested on the same line, the same master cannot not be modified for the different works, creating an imbalance
between the work and the master. Consequently, even if there are no leaks, a differential pressure will be generated. Both the Master and Fitting
tests are methods we use to solve this problem.
With Masterless testing, the differential pressure (noise) that is generated even in the absence of a leak is negated by using Fitting testing.
Ordinary testing methods will not yield the same result.
However, a problem arises from the fact that the collected master data changes over time and the data will eventually not correspond correctly.
Due to this, it became necessary to perform a second fitting test.
Fitting testing uses wave analysis to separate the leak component (proportional to time) from the rest of the input data. To accomplish this, and
resist environmental fluctuations, we generate this fit to the ideal. Since there are data decomposition and operating capacity limitations with the
FL-601, extended time becomes available through fitting testing. The work characteristics and other vital information can be collected
beforehand, making ordinary testing operations easier and less daunting.
Q2: Fitting testing uses detected differential pressure tendencies to conduct wave analysis. Is it possible for the
differential pressure to stray off pattern?
A2: Some differential pressure waves are off pattern.
With differential pressure air leak testers, since the work is enclosed with compressed air, insulated compression causes heat to be generated
internally. By insulating the charge pressure valve and creating a hermetically sealed environment, the heat generated will eventually radiate
into the environment. This hermetic seal changes the internal temperature, creating a pressure change. This is the detected differential
pressure change (noise). This change in differential pressure alters the work's heat radiation, leading the leak tester to express the heat radiation
curve as a pattern. Although this pattern conforms to basic principles, other factors are added to the noise. These are the individual elements
composing the noise:
(1) Peripheral temperature changes.
(2) Source pressure changes.
(3) Internal changes according to work construction and material (the O ring moving, for example).
(4) Internal leaks derived from work construction.
(5) The work heating up due to pre processing influences.
(6) Fluctuations in clamping equipment
(7) Vibration from different processes being conducted side by side.
Changes in (1) and (2) are values from the heat radiation curve and compression heat and will not cause problems with the fitting pattern.
However, sudden changes will offset the test value.
With (3)~(7) it is not possible to attain a proper test value without fitting. However, this noise is common with all differential pressure leak
testers. For these problems, as with past testing procedures, it is necessary to make improvements in labor, facilities and processes.
When fitting cannot be conducted appropriately due to the aforementioned problems, we have prepared models that adapt the data. For more
information, please refer to the basic principle section in this manual.
Countermeasures
Problem
The O ring within the work moves
1
Work changes/deforms shape
2
The clamping seal shifts.
3
Vibrations generated from other
procedures
4
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Use the Turbo function. Apply high pressure in the beginning and test only after the O ring has
moved completely.
Use the Turbo function. Apply high pressure in the beginning and test only after the
deformation settles.
(If the deformation time is consistent, it is possible to obtain the deformation component through
fitting testing)
Press down on the seal, be sure to mount it against metal and clamp it down firmly.
(If it is not possible to have the aforementioned clamping construction, prepare an APU
regulator for each cylinder to remove interference and stabilize the clamp pressure.)
Change the process sequence. If there is a vibration effect on the work during the leak test
(especially during the detection process) do not proceed with the vibration-generating process
until the leak test is complete.
Countermeasure
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