The Sampler™

In development · 2024–present Patent Pending
The Sampler — handheld gold detection device
The Sampler companion App on a Samsung S24

Description

The Sampler is a portable, handheld pipe metal detector designed for gold fossickers. It solves a fundamental problem: traditional gold panning requires water, skill and time — none of which a prospector wants to spend until they know a site is worth working.

Classify a sample through a 3 mm (⅛") sieve, pour it slowly through the Sampler's funnel, and within seconds you know how many gold particles are present and their estimated total weight. The device discriminates between non-ferrous conductive metals (including gold) and ferrous material such as iron and black sand. No water is needed. No panning skill is required.

The Sampler connects to a free smartphone App via Bluetooth, which provides a full session report: particle count, estimated weight in milligrams, and GPS coordinates of the sample site. It runs on any standard USB power bank, drawing under 1 W — enough for 8+ hours in the field.

The device runs an automatic self-calibration on every power-up and ships with a set of colour-coded test beads so the user can verify correct operation at any time.

Technology

The Sampler is based on the Balanced Coil (Induction Balance) metal detection method — the same fundamental technology as many conventional metal detectors — but adapted with several novel innovations for detecting small gold particles in a pipe format:

A side-by-side coil geometry forces sample material through a single receiver coil, enhancing sensitivity and discrimination. An adjustable ferrite collar concentrates the magnetic field and allows fine balance correction. Simultaneous amplitude and phase detection enables discrimination between gold (non-ferrous) and iron (ferrous) particles. An on-device weight estimation algorithm computes the integral of the signal peak to estimate particle mass.

Operating frequency is (TBA)kHz, enabling physically compact coils while maintaining sensitivity to particles from approximately 5 mg (≈0.75 mm diameter) upward. The PIC microcontroller firmware is written in C++ with no third-party RTOS. The companion App is a Progressive Web App (HTML/CSS/JS), communicating via a simple BLE ASCII key-value pair protocol.

Videos

Status

The Sampler is at the working prototype stage. Electronics, firmware and coil set are bench-tested and operational. A provisional patent has been filed.

This project may be open sourced at some point in the future. If you are an experienced gold fossicker interested in field testing, or have a commercial interest in the technology, feel free to get in touch via the About page.

Ownership

© Ex-PD Pty Ltd. "Sampler" and "Flicka" are trademarks of Ex-PD Pty Ltd.

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