MESA 1-D and MESA 2-D: how to confirm the applicable method

The names MESA 1-D and MESA 2-D should not be used as if they represented interchangeable scopes. Before scheduling a test, identify the exact method listing and confirm that its conditions correspond to the system.

What is documented for MESA 2-D

The independent MESA 2-D evaluation classifies it as a nonvolumetric method. It applies vacuum to the tank ullage and uses acoustic signals to detect air ingress, together with a separate water-ingress sensor. The listing identifies capacities, levels, products, waiting time and other limitations.

Why extrapolation is risky

Two methods sharing a manufacturer or equipment family does not prove that they cover the same part of the system, have the same conditions or produce the same kind of evidence. The applicable documentation must be consulted for MESA 1-D; this article does not assign unsupported characteristics to it.

Questions that define scope

• Which tank, line or component needs evaluation?
• What are the product, capacity and level?
• Which exact listing or edition does the provider propose?
• Which conditions can invalidate or limit the test?
• What information will the report include?

Relationship to the Panama procedure

Panamá Digital documents a BCBRP/DINASEPI process for inspecting service stations. Confirm with the authority which procedure and evidence apply to each facility; an equipment name alone does not guarantee acceptance or certification.

The correct decision follows identification of the system, objective and method documentation. If an applicable listing is missing, the responsible status is “pending confirmation.” If the comparison also includes SIR or tracer gas, see our comparison of methods and their scope.