Determination of threshold @ immunity tests

New ideas and suggestions for additional functionality in RadiMation can be added to this forum
Post Reply
Rosu
Posts: 68
Joined: 04 Jan 2012, 15:55

Determination of threshold @ immunity tests

Post by Rosu »

Hi,

the threshold detection is only by decreasing slowly the test level in case of bad behaviour. It would be nice to introduce the possibility to determing the threshold in 2 steps: 1. decreasing the test level till the influence does not exist anymore and after that increasing the level till the influence occures. The last good value of the signal is than the threshold.

Kind Regards,
Marius Rosu
User avatar
joro
Posts: 440
Joined: 24 Aug 2011, 09:55
Contact:

Re: Determination of threshold @ immunity tests

Post by joro »

Regarding the threshold detection of the EUT:
It is indeed correct that the threshold detection is currently slowly decreasing the test level when influence of the EUT is detected. This threshold detection is stopped as soon as it is detected that the EUT is not influenced anymore. The testlevel at that moment is marked as being the maximum testlevel for which the EUT is susceptible. This is the maximum performance testlevel.

You suggested:
decreasing the test level till the influence does not exist anymore and after that increasing the level till the influence occures. The last good value of the signal is than the threshold.
This is indeed an improved algorithm which can be more accurate if the EUT seems to have some hysteresis. Your suggested algorithm is however also taking more time, because an additional number of steps may be required to determine the correct test-level.
Is there a standard which describes that your suggested algorithm should be used to determine the susceptibility level?
Rosu
Posts: 68
Joined: 04 Jan 2012, 15:55

Re: Determination of threshold @ immunity tests

Post by Rosu »

Yes it is described in the FORD EMC-CS-1.9. You can take a look at this on following link: http://www.fordemc.com/docs/download/EM ... 09rev1.pdf , page 32
User avatar
joro
Posts: 440
Joined: 24 Aug 2011, 09:55
Contact:

Re: Determination of threshold @ immunity tests

Post by joro »

Ok. The standard specifies (on page 32):
Testing shall be initially performed using Level 2 requirements. If deviations are observed, the stress level shall be reduced until the DUT functions normally. The stress level shall then be increased until the deviation occurs. The stress level at this point shall be verified to meet the performance requirements delineated in Table 1-1. If the performance requirements are not met, the stress level shall be reported as the deviation threshold.
User avatar
joro
Posts: 440
Joined: 24 Aug 2011, 09:55
Contact:

Re: Determination of threshold @ immunity tests

Post by joro »

We agree that your suggested algorithm is indeed an improvement to the currently implemented algorithm.
We have created a new wish in our database regarding this request.
It is now registered as: #4092: Determination of minimum performance threshold accoording to Ford standard
Rosu
Posts: 68
Joined: 04 Jan 2012, 15:55

Re: Determination of threshold @ immunity tests

Post by Rosu »

Thx :)
Post Reply