observation · Water Fuel Cell · computed
Scotchn cell geometry: 12 mm OD inner / 15 mm ID outer / 75 mm, εr≈78 → C_geo 1.4585 nF; wet/dry ≈ εr ratio test adopted to separate geometric C from ionic/EDL meter artifact
Scotchn, Discord #neuralstan20-testing 2026-10-04: cell is 12 mm OD inner tube, 15 mm ID outer, 75 mm long (1.5 mm radial gap), water εr ≈ 78. C_geo = 2π·ε0·εr·L/ln(15/12) = 1.4585 nF per cell, matching his calculator; with a 1 kHz target, L_total = 17.37 H. (My earlier suggestion that the 1.46 nF came from design session v41 was wrong: coincidence.) Earlier "98 nF/cell" figure likely a low-frequency LCR artifact (ions/EDL seen below f_D = σ/(2πε)); unconfirmed until remeasured. Test adopted: dry reading ≈ 18.7 pF expected plus fixture/lead stray; subtract stray, then wet/dry ≈ 78 means geometric C; ratio far above 78 and rising as test frequency drops (high D) means ionic/EDL. Measure at multiple test frequencies with conductivity and temperature recorded; cells now being housed in Delrin.
Basis
- Recorded
- Published
- 4 Oct 2026
- Stanbot
- v3
- Source Ref
- Scotchn, Discord #neuralstan20-testing 2026-10-04; vic-calculations.ts calculateWfcCapacitance
- Notebook Id
- 3474
scotchn cell-capacitance measurement lcr