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31 free calculators and 148 guides for calibration, uncertainty, mapping and validation. Every number shows its working.

All 31 calculatorsBrowse 148 guides in 11 topics

The arithmetic follows

  • JCGM 100 (GUM)
  • ILAC-G8
  • ISO/IEC 17025
  • IEC 60751
  • IEC 60584-1
  • NIST ITS-90
  • ICH Q1A(R2)
  • EU GDP

Four kinds of team. Four different first questions.

Same tools underneath — what changes is where you come in. Open yours.

The maths, done properly. Free, no sign-up.

Each one prints the formula it used and names the standard it follows.

Calibration certificate checker (ISO/IEC 17025 clause 7.8)Paste the text of a calibration certificate and screen it against ISO/IEC 17025:2017 clause 7.8: uncertainty with k, traceability, as-found and as-left, the decision rule behind a pass, and every other required element, with the matched text shown for each.Open the toolType A uncertaintyPaste a column of repeated measurements and get n, the mean, the sample standard deviation, the standard uncertainty of the mean and the degrees of freedom — laid out in the fields the uncertainty budget calculator asks for, including the ν that most budgets quietly drop.En numberWork out En from your result, the assigned value and both expanded uncertainties, with the z-score and z′ where the scheme states a standard deviation for proficiency assessment. It also shows how much of a pass was bought by the uncertainty you claimed.Protocol builderBuild a draft IQ, OQ and PQ protocol for a cold room, chamber, autoclave or vehicle — document control, the test list that suits that equipment, record tables and approval blocks. It will not write your acceptance criteria, and says so.Mapping analyserPaste the export from a finished mapping study and get the gradient, the hot and cold spots, MKT and per-sensor statistics — plus the data-quality checks that catch a channel which quietly stopped reporting on day two.Calibration intervalPaste an instrument's as-found history and see how fast it is actually drifting, how much of its tolerance that consumes, and how long the evidence supports trusting it. The strongest input to an interval is the instrument's own record — this reads it.Thermal lag simulatorYour cold room alarmed at 3 a.m. and the air was above 8 °C for twenty minutes. Whether the product ever got there depends on its thermal mass — work out the time constant for your load and see how much of that excursion it actually followed.Mapping placement plannerLay out logger positions in a room, see the layout in three dimensions before you climb a ladder, and export the position table for the protocol. It shows you the gaps in a grid — it does not tell you how many loggers to use, and it explains why not.TUR calculatorWork out whether a laboratory's uncertainty is good enough for your tolerance, on the 4:1 basis ANSI/NCSL Z540.3 uses — and see why a healthy TAR can hide a failing TUR.Calibration curvePaste your reference and indication pairs — a calibration curve or a standard curve, the fit is the same — and get the least-squares line, the residual plot that decides whether to believe it, and the residual standard deviation your uncertainty budget needs.Uncertainty budgetCombine Type A and Type B components per the GUM: divisors by distribution, sensitivity coefficients, u_c, effective degrees of freedom and U at k = 2.Guard band / decision ruleTurn a tolerance and an expanded uncertainty into acceptance limits under ILAC-G8 rules, and see the false-accept and false-reject risks.MKT & logger data checkPaste logger readings from storage or a cargo shipment: MKT per ICH Q1A(R2), time out of range, and which figure actually governs the excursion.Pt100 converterConvert between resistance and temperature for Pt100 / Pt1000 sensors, with class AA, A, B and C tolerances at that temperature.Dew point / RHConvert between temperature, relative humidity and dew point, and see how much a temperature error shifts an RH reading.Sampling intervalSee what a logger actually records from the same 24 hours at 1, 5, 15, 30 or 60 minute intervals, and watch a real excursion disappear.Thermocouple mV ↔ °CConvert between millivolts and temperature for type K, T, J, N and E using the NIST ITS-90 reference functions, with proper cold-junction compensation and IEC 60584-1 tolerance classes.Equipment selectorState the range, the uncertainty you need and what you are calibrating. See which class of equipment fits, from dry block to liquid bath, chamber, furnace or blackbody, with the criterion behind every verdict.Laboratory finderState the range, the uncertainty you need and what you are sending for calibration. See which accredited laboratories cover it, with the CMC and accreditation number behind every match.Temperature converterConvert a temperature between Celsius, Fahrenheit, kelvin and Rankine, and convert a temperature difference or uncertainty separately, because the two do not follow the same rule.Pressure converterConvert between Pa, kPa, MPa, bar, mbar, psi, atm, mmHg, Torr, inHg, water columns and kgf/cm², and move between gauge and absolute pressure with the local atmosphere.4–20 mA calculatorScale a 4–20 mA signal to engineering units and back, see where it falls against the NAMUR NE 43 fault thresholds, and get the five-point calibration table for your range.Accuracy spec calculatorTurn a datasheet accuracy such as ±(0.1 % of reading + 0.05 % of full scale + 2 counts) into the absolute error at your reading, and see how it grows as the reading falls.NTC thermistorConvert an NTC thermistor's resistance to temperature and back with the beta equation, or fit Steinhart–Hart coefficients to three calibration points and use those.Wet-bulb humidityEnter the dry- and wet-bulb readings from a psychrometer and the station pressure to get relative humidity, dew point and vapour pressure, with the psychrometer coefficient shown.Balance minimum weightPaste ten or more replicate weighings, or enter a standard deviation, and get the smallest net weight your balance can weigh to 0.10 % accuracy, with the USP readability floor applied.pH slope & offsetEnter the millivolt readings your pH electrode gives in two or three buffers and get the slope as a percentage of the ideal Nernst value, the offset at pH 7, and a check against your own limits.Pt100 lead wire errorSee how many degrees your Pt100 or Pt1000 cable adds to the reading in a 2-, 3- or 4-wire circuit, and how long a 2-wire run can be before the error passes a limit you choose.Pressure gauge calibrationPaste the reference and gauge readings from a calibration run and get each point's error, the hysteresis between the rising and falling series, and the head correction people forget.Calibration worksheetPaste the readings from a calibration and get the error at each point, the test uncertainty ratio, and a pass, conditional pass, conditional fail or fail under the guard band you choose — as found and as left — with a draft record to copy.Qualification workspaceRun a qualification, not just write it. Record each IQ, OQ and PQ test's result against your own acceptance criterion, raise and close deviations, see what stops a stage closing, and export a summary. Your work is kept in this browser.All 31 tools

Also computed from the equations, not copied from a book: Pt100 and Pt1000 resistance tables and thermocouple millivolt tables.

Logger export in. Reviewed mapping report out.

It checks the data before it trusts it, finds the hot spot, the cold spot and every minute out of range, then waits for a person to sign.

  1. 01

    CSV/XLSX

    12 sensors, 72 h, 5 min interval

  2. 02

    Pre-flight

    10,368 readings parsed

  3. 03

    Data quality

    no gaps, no stuck sensors

  4. 04

    Statistics

    min 3.1, mean 5.4, max 8.4 °C

  5. 05

    Hot and cold spots

    cold S02, hot S07

  6. 06

    Excursions

    1, 14 min above 8.0 °C

  7. 07

    Draft report

    marked needs review

  8. 08

    Human review

    not signed off

Demo data
app.valitrac.com/mapping/study-24
NEEDS REVIEWDraft, not technically approved. Cold room CR-2, 12 sensors, 72 h, 5 min interval.
Min
3.1°C
S02
Max
8.4°C
S07
Mean
5.4°C
Excursions
1
S07, 14 min above 8.0 °C
Per-sensor summary (demonstration data)
SensorLocationMin °CMax °CMean °CFinding
S02Rack A, bottom, near door3.16.24.6Cold spot
S05Rack B, middle4.46.95.5In limits
S07Rack C, top, near light5.08.46.3Hot spot · excursion
S11Geometric centre4.66.75.4In limits

Example study, every sensor shown. Not client data.

Temperature mapping beta

Next: Metrology, Monitoring. Roadmap

Guides that answer in the first line.

The answer first, then the working, then the standard it rests on.

All 148 guides

Plus 6 checklists, 8 learning paths, templates and a glossary in the resource centre.

Three complete ISO/IEC 17025 documents, free.

Whole documents from the 116-document pack, no email asked. The full pack is $299, once.

Read the free documentsWhat is in the pack

What is live, what is in beta, what is next.

Live

  • AI technical assistant

    Evidence-backed answers with citations, deterministic uncertainty calculations, validation status and feedback.

  • Insights and glossary

    Technical articles (currently drafts under review) and a searchable metrology glossary.

In beta

  • Temperature mapping engine

    Intake, unit gate, data-quality checks, statistics, hot/cold spots, excursions and a reviewed draft report. Signed-in accounts can upload a logger export and get the draft analysis back; the reviewer interface that records an approval is still in progress.

  • Human review workflow

    Reviewer checklist, request-changes, approve and reject states, and an audit trail. Built for mapping reports; the interface is still in progress.

  • Calibration worksheet

    Readings in, a decision at every point out: error, test uncertainty ratio, ILAC-G8 guard band, as found and as left, with a draft record. A worksheet in the browser, not a certificate.

  • Qualification workspace

    A protocol builder and an execution workspace for IQ, OQ and PQ: results against your own criteria, deviations tracked to closure, a summary to export. Kept in your browser; not a validated system of record.

  • Laboratory finder

    Find accredited calibration laboratories by temperature range and required uncertainty, matched against the CMC on each published scope. A small starter catalog of cited UKAS and A2LA laboratories, not a directory.

Next

  • Accounts, projects and dashboard

    Authentication, tenant isolation and a customer workspace at app.valitrac.com.

  • Calibration workflow and certificates

    Saved jobs, technical review and sign-off, and issued certificates: DUT → method → equipment → reference → measurements → uncertainty → review → certificate.

  • Continuous monitoring

    Live ingestion, alerting and excursion records. The calculators for it are live; the monitoring service is not.

Ask it something you already know.

It is the fair test. Every answer shows the sources it used, the sum it ran and whether it is sure.

Ask a technical questionTalk to an engineer
Example output
valitrac.com/ai

How should a Pt100 be calibrated?

VALIDATEDConfidence: high · 2 sources

Calibrate by comparison against a reference thermometer at a series of stable temperatures across the working range, immersed to sufficient depth in a dry-block or liquid bath, and evaluate the uncertainty budget per GUM. [E1] [E2]

[E1] · experience_report
NPL/NCC digital calibration certificate case study
[E2] · authoritative_standard
EURAMET.T-S7 comparison report
Engineering calculation
u_c = 0.0583 °C → U = k·u_c = 0.12 °C (k = 2)

Validated means every claim matched a source you can open. How answers are checked