Too Small to Burn: Intrinsic Safety, IEC 60079-11 and 60079-25, Entity Parameters, FISCO and Ethernet-APL

Deep End Era. Engineering with Sankalp · Oct 28, 2026 · 1h 2m

The cheapest-looking box on the hydrogen skid is a plastic-bodied pressure transmitter with no heavy enclosure at all, and it is going into the Zone 1 envelope next to the compressor seals. Rashid explains why it is safe, Elena does the loop arithmetic on a whiteboard, and Joseph shows what a single wrong spare part can do to the whole calculation.

Chapters

00:00:00 Cold Open: The Lightest Box on the Skid

00:04:51 How Small Is Small? Sparks, Curves and Hot Surfaces

00:11:08 The Other End of the Wire: Associated Apparatus, Barriers and Isolators

00:16:57 The Whiteboard: Doing the Entity…