Stockpile survey services

Stockpile surveys estimate bulk commodity quantities when weighing all material is impractical. A survey measures the pile's volume and combines it with representative bulk-density data to estimate mass.

Measurement principle

Estimated mass = surveyed volume × representative bulk density. A total station or other suitable survey equipment records the pile geometry. Software processes the measured points and the base model to calculate volume.

Bulk density is determined from sampling and measurement appropriate to the material. Moisture, particle size, compaction and sampling access can affect the result.

Survey procedure

1. Confirm pile identities, boundaries, material descriptions and the reference date.
2. Review site access, visibility, the base surface and safe working arrangements.
3. Measure pile geometry and retain the survey data.
4. Determine representative bulk density and record sampling limitations.
5. Calculate volume and estimated mass, check the results and prepare the report.

Conditions and limitations

• Material should not move during measurement; changes may require a repeat survey.
• Obstructed surfaces and assumptions about the base affect the volume estimate.
• Surface-only sampling may not represent compacted material deeper in the pile.
• Commodity descriptions supplied by the client do not constitute certification of grade or identity.
• The reported quantity relates to the stated survey date and time.
• Weather, visibility and site conditions can affect the work.

Accuracy and equipment

Figures such as ±1% or ±3% in older descriptions are indicative experience-based figures, not a guaranteed tolerance for every stockpile. Achievable uncertainty depends on geometry, sampling, density and site conditions. Equipment specifications must be checked for the instrument actually used.

Battery power alone does not establish suitability for hazardous areas. Equipment and work methods must satisfy the manufacturer's instructions and site safety requirements.

Method references

The ISO 7507 series concerns calibration of vertical cylindrical tanks; it does not itself establish a universal standard for stockpile mass measurement. Any accreditation claim must be checked against the provider's current scope.

For the broader ITVC service overview, see stockpile quantity survey services.