Phi-River Gradient Sensor (Æ Detector)

Differential phi-potential measurement — detects scalar potential gradients invisible to conventional instruments

$195 plan

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// Blueprint rendering available after purchase

Technical Specifications

Classification Scalar EM — Detection

Topology Differential electrostatic bridge

Common-Mode Rejection >80 dB transverse EM rejection

Reference Internal 10 kHz lock-in oscillator

Output Analog + USB data logger

Sensitivity 10 μV/m equivalent phi-gradient

Difficulty 2 / 5

Est. Build Cost $350–$600

Est. Build Time 2–4 weeks

Overview

The Phi-River Gradient Sensor (named for the phi (φ) scalar potential and the "river" gradient it measures along a flux path) is a differential instrument designed to detect scalar potential gradients that produce no conventional magnetic or electric field signature detectable by standard instruments. The sensor uses a matched-pair electrostatic probe array in a Wheatstone bridge configuration, with common-mode rejection >80 dB for transverse EM. The bridge output feeds a precision lock-in amplifier stage referenced to an internal 10 kHz oscillator, enabling detection of static and slowly-varying phi-potential gradients. Applications include mapping scalar field topology around energy devices, geopathic stress zone characterization, and baseline measurement for scalar EM research setups. Build plans include PCB Gerber files, matched probe fabrication guide, and calibration procedure.

Intended Research Use

Scalar potential gradient mapping, phi-potential differential measurement, geopathic stress zone characterization, baseline scalar field characterization for research setups.

Bill of Materials (12 components)

#Component

01 Electrostatic probe electrodes, brass (25mm dia., ×4)

02 Precision resistor network (0.1% tolerance, ×8)

03 INA128 instrumentation amplifier (×2)

04 AD630 balanced modulator/demodulator IC

05 Internal reference oscillator (10 kHz TCXO)

06 14-bit ADC, USB interface (×1)

07 PCB (Gerber files included in plan)

08 Aluminum shielded enclosure (Hammond 1590)

09 BNC probe connectors (×4)

10 Regulated ±12V supply

11 PTFE standoffs for electrostatic isolation

12 Calibration reference source (plan included)

Get Build Plan

Complete plan PDF including all specs, winding geometry, drive circuit schematics, measurement protocols, and Gerber files where applicable.

$195 one-time

Purchase plan — Stripe

Also available: Component kit $950 — members get 10% off

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Complete build documentation (PDF)

Winding specs + circuit schematics

Measurement + verification protocols

Sourcing guide for all BOM items

Lifetime access, no subscription

Build Difficulty

Accessible — good first build for newcomers to scalar EM.

Est. cost: $350–$600
Est. time: 2–4 weeks