Why Ranges are not conformity

In the measurements grid you see two things side by side that look alike but do completely

different jobs: the RANGES column and the CONFORMITY column. One interprets, the

other states.

An example that separates them

A medical check-up:

• "Is your diet healthy?" → an interpretation / advice: low / adequate / high. You don't

"pass" or "fail" — the situation is interpreted and a recommendation is given. That's a

Range (interpretation, §7.8.7).

• "Does the result meet a rule/law?" → a statement: conforms / does not conform. That's an

Acceptance Criterion (statement of conformity, §7.8.6).

The same result can be agronomically "adequate" AND at the same time have no conformity

statement at all — because there's no specification to judge it against.

Ranges (interpretation — ISO/IEC 17025 §7.8.7)

Ranges are agronomic interpretation bands for an element (low/high value, desired value, and a

name like "low / adequate / high").

• Answer: "How is this value interpreted for the crop?"
• They feed the interpretation and the fertilizer Recommendations — not pass/fail.
• They never produce ✓/✗. They're an opinion/interpretation, not a conformity statement.
• Shown in the RANGES column (e.g. "6 – 8") as a reference frame for the reader.

Acceptance Criteria (conformity — ISO/IEC 17025 §7.8.6)

An Acceptance Criterion judges the result against a specification and issues a conformity

statement (see "Why two kinds of limits").

• Answers: "Does the result meet the requirement?"
• Produces the CONFORMITY column (✓ / ✗ / ⚠ / —).
• Exists only when a real specification exists (law, customer agreement, standard).

Why they must not be confused

A Range's limits ("6 – 8", what counts as a good Ca/Mg ratio) are not a conformity spec. If

there's no Acceptance Criterion, the CONFORMITY column correctly shows "—", while the Range

keeps giving the agronomic interpretation. One doesn't override the other — and one shouldn't be

read as the other. (That's why, when a ✓/✗ does exist, the LIMS shows the Acceptance Criterion

limits beneath it — so it isn't confused with the Range band.)

At a glance

The practical rule

Ranges = advise (what the value means). Acceptance Criteria = state (it meets a requirement).

Most soil parameters have Ranges but no Acceptance Criterion — and that's correct.