When people talk about the “sweet spot” on the NCB dial, they’re referring to the setting that achieves two key results simultaneously:

1. Blocks nuisance (contact) current from flowing through your grounding device, making it safer.

2. Minimizes electric fields on your body that can arise when too much resistance is added.  

How to Find the Sweet Spot

Shield Your Body provides a tested method, typically done with EMF meters:

• Use two meters:

  • A Fluke meter to measure current flowing through your body.

  • A NFA‑1000 meter to measure electric field strength near you.  

• Step-by-step:

  1. Plug in the NCB and connect your grounding product.

  2. Position the Fluke between your hand and the mat, and note the current reading.

  3. Twist the NCB dial slowly:

     • Turning it left increases resistance, reducing current flow.

     • Turning it right decreases resistance, allowing more current.

  4. When the Fluke shows near-zero current, check the NFA‑1000 reading:

     • You’ll see the electric field strength shift as resistance changes.

  5. The ideal “sweet spot” is where:

     • Current is minimized (at safe, near-zero level), and

     • Electric fields stay low, not rising in response to excessive resistance.  

Can’t Use Meters?

If you don’t have these meters, many users find it easier to adjust the dial one full turn counter-clockwise (to the left) from its starting position. This typically lands near the optimal balance for safe grounding while keeping electric fields low.

Why It Matters

Without the sweet spot:

• Too little resistance → Current still flows, which could pose bodily exposure risks.

• Too much resistance → Electric fields increase, creating another type of exposure risk.

The sweet spot gives you just enough resistance to safely block current without raising electric fields—ensuring your grounding session is both effective and protected.