Why Selecting the Correct Coin Matters for Accurate Ping Test Results

Important: The app cannot see your coin. It will always assume the selected coin is correct, even if it isn't.

Quick Checklist Before You Test

  • ✅ Same weight? (Check the app's displayed weight)
  • ✅ Same diameter? (Check the app's displayed diameter)
  • ✅ Same material? (Check the app's displayed metal: gold or silver)

If any answer is "no", the test result is invalid.

The Golden Rule

If the coin in your hand doesn't have the same weight and diameter as the coin selected in the app, the result is invalid, even if it shows "pass" or "fail."

This is the most common mistake users make, and it's easy to do. But once you know this rule, you'll get reliable results every time.

Common (Wrong) Examples

These are real mistakes users have made:

Testing Eisenhower Dollar as Washington Quarter:

  • App setting: Washington Quarter (6.25 g, 24.3 mm)
  • Physical coin: Eisenhower Dollar (31.1 g, 40 mm)
  • Result: Invalid (different weight and diameter)

Other similar cases:

All of these invalidate the test because the weight, diameter, or material don't match.

How to Get Accurate Results

Step 1: Identify Your Physical Coin

Before opening the app:

  • Read the coin’s inscription and design
  • Note the coin name, country, and denomination
  • Check the year if multiple versions exist

You should have a clear idea of what coin you are holding.

Step 2: Select the Matching Coin in the App

In the app, choose the coin that matches the material and design of your physical coin. This tells the app which coin you intend to test.

Step 3: Verify Weight and Diameter (Critical)

After selecting the coin, the app displays the reference specifications. Pause for 3 seconds and confirm:

  • Weight (g) matches your coin
  • Diameter (mm) matches your coin
  • Material (gold or silver) matches your coin

These values are non-negotiable. If any of them don't match, you selected the wrong coin and the test result will be invalid.

If you are unsure about your coin's specifications:

  • Weigh the coin on a precision scale
  • Measure the diameter with calipers
  • Turn on the Customization option and enter the real parameters

Step 4: Final Sanity Check

Confirm all three before testing:

  • Material matches ✓
  • Weight matches ✓
  • Diameter matches ✓

If all match, you are ready to proceed.

Why This Rule Exists

Ping testing works because coins with the same weight and diameter but different materials always produce different sounds.

For example:

  • A genuine Silver Eagle (40.6 mm, 31.1 g) has a specific acoustic signature
  • A fake with the same dimensions but different metal sounds different
  • The app detects this difference

But this only works when weight and diameter match. Different coins can sometimes sound similar, but that similarity is meaningless when comparing coins of different sizes.

Common Pitfalls to Avoid

Trusting appearance over specifications:

  • Silver Eagle and Gold Eagle look similar, but have different sizes and materials
  • Same-year Britannia coins in different denominations look similar, but have different sizes

Always verify by checking the displayed weight and diameter, not just the coin's appearance.

Testing the app's reliability:

Some users would like to test the app's reliability by using a different coin as a test case. This is an invalid approach because it violates the matching parameter rule.

The best option is to use Customization Mode if you don't have a fake coin. For example, if you have a Silver Britannia, you can set the parameters as:

  • Set diameter: 38.61 mm (same as Silver Britannia)
  • Set weight: 31.1 g (same as Silver Britannia)
  • Select metal: Gold (different material)

Then test the Silver Britannia. The app should correctly fail this test because you're asking: "Is this 31.1 g, 38.61 mm coin made of gold?"

Bottom Line

The app doesn't know what physical coin you're holding—you must tell it correctly by selecting the matching coin.

Remember: Check weight, diameter, and material first. If they all match, you're good to test. If any don't match, the result will be invalid no matter what it says.

This simple check takes seconds but makes all the difference between reliable results and wasted tests.