I have tested systems to the heavy industrial immunity specification which
included class B PCs. Both HP Vectra computers and Dell computers faired
well. Ocassionally the monitors sold with these systems are disturbed to
the point of turning themselves off (a failure in most books). To date
I've always been able to solve this problem by upgrading to an NEC
multisync monitor. The key distinquinction of all these products is that
they really do meet class B by wide margins and use very good shielding to
get to that level. Once you have shielding that good and use digital
techniques inside (as opposed to small signal, high impedance analog
signals - thermocouples, etc.) heavy industrial immunity compliance is
usually a given.
Jon D. Curtis, PE
Curtis-Straus LLC j...@world.std.com
One-Stop Laboratory for EMC, Product Safety and Telecom
527 Great Road voice (508) 486-8880
Littleton, MA 01460 fax (508) 486-8828
http://world.std.com/~csweb
On Wed, 12 Feb 1997, Tony Fredriksson wrote:
>
> If such a system is not easy to find, is there any reason why one can't use
> two systems to test an expansion card?
>
> One could be CE marked and declared for Class B ( a PC) and the
> other could be a system that is CE marked and declared for Heavy
> Industrial Immunity. In this way, you have shown the card to be compliant
> with both standards and do not need to search for one system that has
> all of the approvals.
>
> Is this acceptable?
>
> Regards,
> tony_fredriks...@netpower.com
>
> ----------
> From: comp_lab
> To: EMC-PSTC
> Date: Wednesday, February 12, 1997 2:38PM
>
> Hello All,
>
> We are doing something out of the usual for us and have developed a product
> that is a card designed to go in a PC. For our normal products, with
> regards to the EMC directive, we do industrial immunity and Class B for
> emissions. We would like to do the same for the PC card. The problem is I
> haven't found a PC yet, that has been previously tested to the industrial
> immunity standard AND class B. If anybody knows of any systems that will
> pass these tests please let me know.
>
> Thanks for your help
>
> Regards,
>
> ---------------------------------------------------------------------
> Kevin Harris
> Manager, Compliance Engineering
> Digital Security Controls
> Toronto, Canada
> 416 665-8460 Ext 378
> ---------------------------------------------------------------------
>
