Turn your phone into a metal detector
The phone in your pocket already has a magnetic sensor. This guide explains how it works, how to get accurate readings with Metal Detector & Gold Hunt, and what its real limits are.
How does a phone detect metal?
Almost every Android phone has a magnetometer, the same component that lets your maps app know which way you're facing. It measures the strength of the surrounding magnetic field in microtesla (μT).
Normally, your phone only "hears" the Earth's magnetic field, usually somewhere between 25 and 65 μT depending on where you are. Bring the phone close to something made of iron, steel or a magnet, and that object distorts the local field, so the number on screen jumps. The app tracks these changes in real time and alerts you with a needle gauge, a beep and a vibration.
The effective detection range is about 20–25 cm (8–10 inches). The bigger the object and the more iron it contains, the farther away it can be picked up.
Key features
Beyond metal detection, the app bundles several tools that use your phone's sensors:
Metal detector
Shows magnetic field strength in real time and alerts you with sound and vibration when metal is nearby.
Gold mode
A dedicated mode with a live graph, so you can spot small changes while scanning around jewelry and other items.
Stud finder
Sweep along a wall to locate nails, screws and metal framing before you drill or hang a picture.
Hidden camera detector
Combines magnetic scanning with an infrared scan through your camera to check hotel rooms or changing rooms.
Compass & location
A compass with your coordinates, city name and elevation. Handy for hikes and outdoor trips.
Gold price
Check the current gold price without opening another app.
Five view modes
It's the same sensor data, but everyone reads it differently. Switch between these modes at any time:
| Mode | What it shows | Best for |
|---|---|---|
| Meter View | A classic detector-style needle gauge | Seeing signal strength at a glance |
| Digital View | A large, clear μT number | Finding studs, comparing spot by spot |
| Graph View | A graph over time | Catching small changes during slow sweeps |
| Sensor View | Field values on the X, Y and Z axes | Working out which direction the object is in |
| Camera View | Live camera feed with readings | Looking and scanning at once, finding hidden cameras |
Get started in 4 steps
- Open the app and pick a view mode. If you're new, start with Meter View. It's the easiest to read.
- Calibrate the sensor. If the app shows sensor accuracy as Low or Unreliable, move your phone in a figure-8 motion about 4 times until it switches to High.
- Note your baseline. Stand away from metal objects and check the μT reading. That's the "normal" level where you are.
- Sweep slowly and steadily. Hold the phone parallel to the surface, a few centimeters away. When the reading climbs and the app beeps, you're close to your target.
Where is the sensor? On most phones, the magnetometer sits near the top of the device, close to the front camera. Scan with the top edge of the phone rather than the middle.
Tips for more accurate readings
- Remove magnetic cases and wallet covers with magnetic clasps. They throw off the reading from the start.
- Stay away from electrical devices such as speakers, fridges, microwaves or live power cables while measuring your baseline.
- Recalibrate when you change location. The magnetic field differs indoors, outdoors and inside a car.
- Turn on sound and vibration in Settings so you don't have to watch the screen while sweeping a large area.
- Scan in a grid. When looking for studs, sweep across the wall row by row and mark the spots with the highest readings.
What the app can and can't do
A phone can't replace a dedicated metal detector, and we'd rather you know that up front than be disappointed later.
Detects well
- Iron, steel and nickel objects: keys, nails, screws, tools, household items.
- Magnets and electronics with magnetic parts, such as small speakers and some cameras.
- Nails and metal framing inside drywall or wooden walls.
Hard or impossible to detect
- Pure gold, silver, copper and aluminum. These metals aren't magnetic, so they barely affect the magnetic field. Gold mode responds best to jewelry that contains alloys or has steel clasps and fittings.
- Objects buried deep underground or more than about 25 cm (10 inches) away.
- Wireless cameras made entirely of plastic, far away, or switched off.
Treat it as a helper tool. Before drilling into a wall, also check your home's wiring layout. If you suspect a hidden camera, report it to the property or to the authorities.
FAQ
Will it work on my phone?
Most modern Android phones have a magnetometer. If yours doesn't, the app will show "This Device Sensor Not Supported" as soon as you open the detector.
Why does the reading jump around when there's no metal?
Usually the sensor hasn't been calibrated, or there's an electrical device or magnetic case nearby. Move your phone in a figure-8 a few times, then measure again somewhere more open.
Does the app need an internet connection?
Metal detection runs entirely on your phone's sensor, so no connection is needed. Gold prices and location details need a connection to load data.
What languages does the app support?
Nearly 20 languages, including English, Spanish, French, German, Portuguese, Hindi, Arabic, Japanese, Korean and Chinese. You can change the language and switch between light and dark themes in Settings.
What do I get with VIP?
VIP unlocks every detector mode without watching ads, removes ads entirely and gives you a dedicated support channel.
Try it on your phone
Download Metal Detector & Gold Hunt for free, calibrate the sensor in seconds and start scanning.
Get it on Google Play
Comments
Post a Comment