How accurate is stockpile measurement?

The short answer

With a good capture, Stockpile measures a pile’s volume within about 5%. A tape and formula can be much further out on an irregular pile, because it assumes a shape the pile does not have.

Where the error comes from

• The ground. The volume is measured down to the ground under the pile. A centimetre of ground error across a wide, low pile moves the volume more than anything else. Stockpile fits the ground from a ring round the pile and shows how well it fitted.
• The toe. Where the pile stops and the ground starts. Stockpile traces it for you, and you can move it by hand.
• What was not seen. Gaps and out-of-reach tops. Stockpile marks unseen areas in red, leaves gaps out and counts an unseen top as estimated, so you know how much was measured.
• Material weight. For tonnes, the density you choose matters as much as the volume. See cubic metres to tonnes.

How to get a good capture

1. Walk slowly, 1.5 to 3 m from the face, all the way round.
2. Keep the toe and some ground in view the whole time.
3. Scan in good, even light.
4. Check the scan verdict and the share measured before you rely on the number.

When to use a surveyor

Stockpile gives indicative volumes for stock management. For volumes that money or contracts depend on, use a licensed surveyor.