How to Field-Test a Long-Range Locator Before Trusting It

The most reliable way to test long range metal detector claims is a blind test: a helper places real targets and empty decoy positions at locations the operator does not know, the operator uses the locator to choose, and every result is recorded and compared with what pure guessing would achieve. If the locator cannot beat chance under blind conditions, its long-range indications should not drive where you dig. This guide gives a step-by-step protocol you can run in an afternoon with one or two helpers.

Long-range and ionic modes are marketed with large range and depth figures that are manufacturer-stated and not independently verified. For background on the claimed principles and the reasons for skepticism, read our explainer on how long-range locators claim to work. A fair test is the best way to settle the question for your own unit on your own ground.

Before you start: three ground rules

1. Test the claim the manufacturer actually makes. Note the stated target types, ranges, depths and any conditions (for example, how long a target must be buried). Design the test inside those limits so the result is fair.
2. Remove every clue. Fresh digging, footprints, flags, a helper's glance or tone of voice can all give away a location. Blind means the operator has no way of knowing other than the device.
3. Decide the scoring before you begin. Write down how many trials you will run and what counts as a hit. Changing the rules after seeing the results is the most common way tests go wrong.

One practical note: read our warranty policy and return terms before field use. Store returns generally apply to unused items in original packaging, so testing in the field may affect return eligibility. If you are unsure, call us before you start.

How to test long range metal detector claims: the blind protocol

What you need

• A test site with permission, clear of buried utilities (call 811 before digging) and away from fences, vehicles and power lines
• Targets that match the claimed target type and size, such as a known mass of the selected metal, sealed in identical containers
• Identical empty containers to use as decoys
• Four or five marked positions spaced well apart (stakes or cones that look identical)
• A die, a random-number app or shuffled cards to choose positions
• A score sheet with trial number, position chosen, true position and notes
• Two helpers if possible: one to place targets, one to record

Step-by-step

1. Prepare the positions. Mark four or five stations. Dig or prepare every station identically, so disturbed soil does not reveal which one is real.
2. Randomize the placement. The placer uses the die or app to choose which station receives the real target. Every other station gets an identical empty container.
3. Keep the placer away from the operator. The person who knows the answer should leave the area or stay out of sight until the trial is scored.
4. Run the search. The operator uses only the long-range or ionic mode, following the manufacturer's procedure, and commits to one station.
5. Record before revealing. The recorder, who also does not know the answer, writes down the choice. Only then does the placer reveal the true position.
6. Repeat. Run at least 20 trials, re-randomizing every time. A handful of trials proves very little in either direction.
7. Add a control series. Run a few trials with a conventional induction coil directly over shallow targets. This confirms that the targets are detectable and that your setup is fair.

Scoring your results against chance

With four stations, guessing alone picks the right one 25 percent of the time. Over 20 trials, you should expect about five correct by chance, and runs of good luck are common. The table below shows how likely it is to reach a given score by guessing alone with four stations and 20 trials.

A single impressive session is not enough. If a result looks strong, repeat the entire test on a different day with fresh randomization. Real effects repeat; luck usually does not.

A simple score sheet layout

Keep the record simple and complete. A paper sheet or spreadsheet with these columns is enough:

Keeping conditions notes lets you see whether results change with weather or soil, which is useful information whichever way the test turns out.

Testing directional and distance claims

Many locators claim to point toward a target from a distance. You can test this too:

1. Place a target (or nothing) at a randomly chosen point the operator does not know.
2. Have the operator stand at a marked starting point, follow the device's indication and record the compass bearing it gives.
3. Repeat from several starting points and for several hidden placements, including trials with no target at all.
4. Compare the recorded bearings with the true bearings. If the errors are spread randomly around the compass, the device is not locating the target.

Trials with no target are essential. A device that "finds" something every time, even when nothing is there, is not discriminating between target and no target.

Common mistakes that spoil a test

• Testing on a site where you already know the target location. This is a demonstration, not a test.
• Letting the person who placed the target stay nearby. Unconscious cues are powerful.
• Counting only the hits. Misses and false signals matter just as much.
• Changing settings or rules mid-test. Decide your procedure in advance.
• Free-swinging antennas held loosely. Tiny, unconscious hand movements can steer the antenna. This is the same ideomotor effect researchers use to explain dowsing.
• Stopping after a lucky streak. Run the full number of trials you planned.

What if the manufacturer says targets must be buried for years?

Some ionic claims state that targets must be buried for a long time before they can be detected. That makes a quick test harder, but it is also important information. A claim that can only work under conditions that are almost impossible to check deserves extra caution. You can still test the parts of the claim that apply to targets you can place, and you can ask the manufacturer what independent testing supports the long-burial claim.

How to use your results

• At chance: Do not rely on the long-range mode to decide where to dig. Use the unit's conventional induction or scanning systems, which can be judged with ordinary shallow tests.
• Above chance, once: Repeat the full protocol before drawing conclusions.
• Consistently above chance under tight blinding: Document your method carefully. Results like that would be notable and worth sharing with the manufacturer.

For more on avoiding inflated claims across the industry, see how to spot metal detector scams and fake depth claims. If you want to compare units by their stated systems, browse our long-range detectors collection.

Frequently asked questions

How many trials do I need to test a long-range locator?

At least 20 per test, and more is better. With fewer trials, lucky streaks are too easy to mistake for real performance.

Can I test a long-range locator alone?

Not properly. Someone else has to place targets so you cannot know where they are. A second helper to record results makes the test stronger.

What targets should I use?

Use the target type and size the manufacturer says the device detects, sealed in containers identical to the empty decoys.

Does a successful demonstration prove a locator works?

No. A demonstration where anyone present knows the target location is not blind. Only blind, repeated trials show whether a device beats chance.

Should I test the conventional coil too?

Yes. A quick control test with the induction coil over shallow targets confirms your targets are detectable and your setup is fair.