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Acidus

Method notes

Method notes

Method changes, proficiency-testing results including the ones we did badly on, and plain explanations of what an uncertainty figure means.

17 September 2026 What accreditation scope actually meansIt attaches to a determination and a matrix, not to a building. How to read a schedule.17 September 2026 A result without its uncertainty is not a resultWhat the figure means, why it is on every report, and why some laboratories omit it.17 September 2026 How to take a water sampleThe four mistakes that make a microbiological result meaningless before it reaches us.17 September 2026 Why we photograph every sample at receptionCondition on arrival is the commonest cause of a disputed result. A photograph ends it.17 September 2026 The two jobs we turned downConflicts of interest we could not manage, and what independence costs in revenue.17 September 2026 The proficiency test we failedA nitrate round in 2023, the cause, the corrective action, and the re-test.

Before you send a sample

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Are you accredited for the test I need?
The test list says so in a column, per determination. Sixty-one are inside our ISO 17025 scope, eleven are run outside scope and marked, and eight per cent of work is subcontracted to two named laboratories. Accreditation attaches to a determination and a matrix, never to a building.
How long will it take?
The working days shown against each test are the measured median for the last twelve months rather than a target. Where a result will be late we telephone before the due date, not after it.
What is on the report?
The result, the measurement uncertainty, the limit of detection, the method reference with its revision number, the sample condition on arrival and the accreditation status of that determination. Every one of those, on every report.
How should I take the sample?
Ask us first for anything microbiological or for potable water. We supply sterile bottles free, and a badly taken sample cannot be rescued by a good laboratory no matter what it costs.

Tell us the matrix and the determination and we will name the method

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