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Measurement Uncertainty Support

Uncertainty Budgets That Hold Up Under Assessment

GUM-compliant uncertainty budgets built, reviewed, and defended by a practicing metrologist — so your CMCs survive the assessor’s review instead of turning into findings.

  • Contributors are missing, double-counted, or carry the wrong divisor
  • Your budgets don’t match the CMCs on your scope
  • Nobody on the team can defend the math in front of an assessor
Get a Free Budget Review See what we handle

Send us one budget. We’ll tell you what an assessor is going to flag — no obligation, no sales pitch.

Typical turnaround: 3-5 Days

Why this keeps going wrong

Uncertainty is where good labs lose points

A lab can run clean methods, keep excellent records, and still walk into an assessment with a budget that doesn’t survive ten minutes of questions. These are the patterns we see most:

  • The budget was inherited from a template and nobody knows where the numbers came from
  • Type B contributors use the wrong distribution or divisor
  • Repeatability was run once, years ago, on a different instrument
  • Sensitivity coefficients are missing where units change
  • The stated CMC is smaller than the budget can actually support
  • Reported uncertainties don’t tie back to any documented budget
  • No degrees of freedom, so the coverage factor is just assumed to be 2
  • Decision rules on reports don’t reference the uncertainty at all

None of this means your measurements are wrong. It means the paperwork behind them can’t prove they’re right — and that is exactly what an assessor is there to test.

How we help

Four ways labs bring us in

Take the whole thing off your plate, or bring us in for the one piece that’s stuck. Both work.

01

Budget development from scratch

You give us the measurand, the equipment, and the method. We deliver a complete, GUM-compliant budget you can hand to an assessor and explain.

  • Model equation and full contributor identification
  • Correct distributions, divisors, and sensitivity coefficients
  • Type A studies designed and analyzed
  • Welch–Satterthwaite effective degrees of freedom
  • Live Excel workbook — not a locked PDF
02

Review, repair & audit defense

Already have budgets? We audit them the way an assessor will, fix what’s broken, and help you answer findings you’ve already received.

  • Line-by-line technical review against JCGM 100:2008
  • Broken formulas and cell references repaired
  • Contributor gaps and double-counting corrected
  • Written responses to uncertainty-related findings
  • Coaching so your team can defend the math live
03

CMC development for your scope

The numbers that go on your accredited scope have to be defensible and achievable. We build CMC statements your lab can actually deliver, every day.

  • CMC statements formatted for your accreditation body
  • Ranges, parameters, and conditions defined correctly
  • Scope expansion for already-accredited labs
  • Budgets tied directly to each CMC line
  • Support through the scope review process
04

EMC & RF specialty budgets

Transient and RF work is where generic uncertainty consulting stops being useful. This is built directly from hands-on EMC budget development.

  • IEC 61000-4-2 & ISO 10605 — ESD contact and air discharge
  • IEC 61000-4-4 EFT/burst, 4-5 surge, 4-11 dips, 4-12 ring wave
  • MIL-STD-461 transient methods
  • Per-measurand budgets across impedance configurations
  • Oscilloscope, attenuator, and network contributors handled properly

What we work against

Standards, bodies, and disciplines

Uncertainty & quality

GUM — JCGM 100:2008 ISO/IEC 17025:2017 VIM — JCGM 200 ILAC-P14 ISO 9001:2015

Accreditation bodies

A2LA ANAB PJLA ILAC MRA signatories

EMC & transient methods

IEC 61000-4-2 IEC 61000-4-4 IEC 61000-4-5 IEC 61000-4-11 IEC 61000-4-12 ISO 10605 MIL-STD-461

Calibration disciplines

Dimensional Electrical Temperature Pressure Mass & force Time & frequency

Testing disciplines

Chemical Environmental Mechanical Microbiological

Tools & systems

Excel / GUM workbooks Qualer LIMS & CMMS Calibration automation

Track record

Built by a practicing auditor and metrologist

Not a documentation shop. The same person who writes your budget has sat on both sides of the assessment table.

Over 100 Uncertainty budgets developed
Over 10 Labs supported
Majority Test & calibration standards covered
GUM JCGM 100:2008 compliant, every time

I am very pleased with the services offered by Precision ISO. They were a valuable asset in preparation for our audit — setting up new uncertainty budgets, professional tips and tricks regarding the audit, along with the great work they do with content development. I look forward to utilizing their services in the future.

Owner / President, Calibration Company — East Coast, USA

How it works

A clear path from unclear to defensible

1

Budget review

Send one existing budget, or just describe the measurement. We tell you where you stand and what an assessor will question.

Free
2

Scope & measurand mapping

We list every measurand that needs a budget and match it to the CMC lines on your scope, so nothing gets missed.

3

Data collection plan

A practical plan for the Type A studies your lab actually has time to run, using the equipment you already own.

4

Budget build

Contributors, distributions, sensitivity coefficients, combined and expanded uncertainty, and effective degrees of freedom — documented and traceable.

5

Handoff & training

We walk your team through every line so they can maintain the workbook and defend it without calling us first.

6

Assessment support

On call during your assessment, and available afterward to help resolve any uncertainty-related findings.

Fit check

Is this the right help for your lab?

This is built for you if…

  • You’re pursuing ISO/IEC 17025 accreditation and uncertainty is the piece nobody on staff owns
  • You’re already accredited and expanding scope with new CMCs
  • An assessor raised a finding against your budgets or your reported uncertainties
  • You inherited spreadsheets nobody can explain or maintain
  • You run EMC, transient, or RF testing and need budgets specific to those methods
  • Your team can do the measurements but not the statistics

Probably not a fit if…

  • You want a generic template with no data behind it
  • You need a number produced without access to your methods or equipment
  • You’re looking for a signature on work you’d rather not have reviewed
  • Nobody at the lab is available to supply measurement data

Common questions

What labs ask us first

How long does a budget take to build?
It depends on how many measurands are in scope and whether the Type A data already exists. A single well-defined measurand with existing data is fast; a full scope with new repeatability studies takes longer. After the free review we can give you a real timeline rather than a guess.
Do we need to give you our measurement data?
Yes — and that is the point. A budget built without your equipment, your environment, and your repeatability data is a template, not an uncertainty statement. If the data doesn’t exist yet, we’ll design the studies so your team can collect it efficiently.
We already have budgets. Is a review worth it?
Usually, yes. Most budgets we see are directionally right but have specific, fixable problems — a wrong divisor, a missing sensitivity coefficient, a CMC that the math doesn’t support. Those are the exact things that turn into findings, and they’re much cheaper to fix before an assessment than after.
Will our team be able to maintain the workbooks?
That’s the goal. You get live, unlocked Excel workbooks with the formulas visible, plus a walkthrough of how each contributor was chosen. When your equipment or method changes, your team updates the budget rather than starting over.
Can you help if we already have a finding against our uncertainty?
Yes. We review what was cited, correct the underlying budget, and help you draft the response so the corrective action actually closes the finding instead of inviting follow-up questions.
What does it cost?
It scales with the number of measurands and how much data collection is involved. The initial budget review is free, and after that conversation we can usually give you a clear breakdown before you commit to anything.
Do you work with labs that aren’t accredited yet?
Often. Getting uncertainty right early is far easier than retrofitting it once your scope is drafted and your methods are locked in. If you’re still working toward accreditation, our ISO 17025 accreditation support covers the full implementation.

Send us one budget. We’ll tell you what an assessor will flag.

Thirty minutes, no pressure, and a straight answer about whether your uncertainty work will hold up — or what it will take to get it there.

Get a Free Budget Review Read the Uncertainty Guide First

Or email us directly: info@precisioniso.com

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