Lab · Prototypes
Split-Core Current Clamp
In test
Accurate to 2% above 1 A, useless below it.
Instrumentation / MagneticsRange0.2–60 A
Error >1 A2%
Error <1 A18%
StartedJul 2026
Progress62%
The question
Can a clamp built from a split ferrite core measure well enough to trust on a bench?
Where it stands
Above 1 A it tracks a reference meter within 2%, which is usable. Below 1 A the error climbs to 18%, dominated by the air gap in the split core — gap reluctance varies with how firmly the halves close, and that varies every time you clip it on.
03Bench log
21 Jul 2026
First clamp assembled from a split ferrite.
14 Aug 2026
Calibrated against a reference meter across the range.
03 Sep 2026
Error traced to gap variation, not to the sense electronics.
04Next step
Next
Add a spring preload so the core halves close to a repeatable pressure every time.