Redundant Instrumentation 1

[controlnovice]

Is there any standard/code which indicates that redundant instrumentation needs to be different technology?

For example: redundant level would need to have radar as one, and DP as the other?

______________________________________________________________________________
This is normally the space where people post something insightful.

 

[lacajun]

Not to my knowledge. Some plants do that on safety systems but most, from my perspective, use the same technology.

 

[IRstuff]

I would think that this depends on the expected failure modes. In ultra-reliable systems, there might be a concern that identical equipment may fail identically, so one might be tempted to use different equipment to ensure that there are no common failures. Such an approach is often taken with spacecraft, wherein multiply redundant computers are programmed by different groups to do the same task, thereby ensuring that data or program glitches that affect one computer will not affect the other.

For more mundane applications, there might be similar situations, where you have to run equipment from different sets of mains to ensure that failures on one main don't propagate to the other devices on a different main.

TTFN

FAQ731-376
Chinese prisoner wins Nobel Peace Prize

 

[KiwiMace]

Boiler water level requires differing approaches to measurement in the redundant systems.

 

[xnuke]

Redundancy means using two or more of the same technology. Diversity means using two or more different technologies. Both are often required in the nuclear industry for safety-related systems by various standards. As IRStuff noted, redundant systems can suffer from common cause failure, which diverse systems may avoid.

xnuke
"Live and act within the limit of your knowledge and keep expanding it to the limit of your life." Ayn Rand, Atlas Shrugged.
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.