Numbers you can defend.
Free calculators, 121 guides and a mapping workflow for calibration and validation. Every number shows its working.
The arithmetic follows
- JCGM 100 (GUM)
- ILAC-G8
- ISO/IEC 17025
- IEC 60751
- IEC 60584-1
- NIST ITS-90
- ICH Q1A(R2)
- EU GDP
The maths, done properly. Free, no sign-up.
Each one prints the formula it used and names the standard it follows.
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.
- 01
CSV/XLSX
12 sensors, 72 h, 5 min interval
- 02
Pre-flight
10,368 readings parsed
- 03
Data quality
no gaps, no stuck sensors
- 04
Statistics
min 3.1, mean 5.4, max 8.4 °C
- 05
Hot and cold spots
cold S02, hot S07
- 06
Excursions
1, 14 min above 8.0 °C
- 07
Draft report
marked needs review
- 08
Human review
not signed off
| Sensor | Location | Min °C | Max °C | Mean °C | Finding |
|---|---|---|---|---|---|
| S02 | Rack A, bottom, near door | 3.1 | 6.2 | 4.6 | Cold spot |
| S05 | Rack B, middle | 4.4 | 6.9 | 5.5 | In limits |
| S07 | Rack C, top, near light | 5.0 | 8.4 | 6.3 | Hot spot · excursion |
| S11 | Geometric centre | 4.6 | 6.7 | 5.4 | In limits |
Example study, every sensor shown. Not client data.
Next: Calibration, Metrology, Validation, Monitoring, Laboratory Discovery. Roadmap
Guides that answer in the first line.
The answer first, then the working, then the standard it rests on.
- Rectangular, triangular and normal distributions in uncertainty budgetsThe assumed distribution sets the divisor that turns a limit into a standard uncertainty: √3 for rectangular, √6 for triangular, √2 for U-shaped, k for normal. Choosing wrongly changes the reported uncertainty by a few per cent, and choosing without saying so is the real fault.Metrology
- Type A vs Type B uncertainty evaluationThe GUM splits components by how they were evaluated, not by what they are: Type A from statistical analysis of repeated observations, Type B from anything else. The split changes nothing about how they combine, and everything about their degrees of freedom.Metrology
- Effective degrees of freedom and when k = 2 is not enoughk = 2 assumes you know your uncertainty well. When a Type A component from a handful of readings dominates the budget, you do not, and the Welch-Satterthwaite calculation says by how much: three readings can push k to 4.53 and the expanded uncertainty to more than double.Uncertainty
- Uncertainty budget for a thermocouple calibrationA thermocouple budget adds inhomogeneity, reference-junction and extension-lead terms to the usual comparison budget. In a realistic type K budget at 400 °C, inhomogeneity alone carries 85 % of the variance — and it is the one term no calibration removes.Uncertainty
- Mean kinetic temperature (MKT): what it is and when to use itMKT is not an average. It is the single temperature that would do the same cumulative chemical damage as the varying profile actually recorded, and because degradation is exponential it always sits above the arithmetic mean whenever the temperature varied at all.GDP / GMP
- Pt100 tolerance classes explained (IEC 60751)Classes AA, A, B and C are limits on how far an uncalibrated sensor may sit from the standard curve, and each widens with temperature. Class A is ±0.15 °C at 0 °C but ±0.55 °C at 200 °C, and none of these figures is a measurement uncertainty.Equipment
- Thermocouple types and tolerance classes (IEC 60584)Types K, J, T, N and E each have a defined EMF curve and tolerance classes 1, 2 and 3. Choose by range, environment and the tolerance you actually need — then remember the tolerance applies to new wire, not to the thermocouple after a year in service.Equipment
- Selecting a reference thermometerThe reference sets the floor of every uncertainty you can deliver. Pick it for stability first and calibration uncertainty second — a reference that drifts between its own calibrations is worse than one with a larger but honest number on the certificate.Calibration
- Self-heating in resistance thermometersThe measuring current dissipates power in the sensing element and warms it above its surroundings. How much depends almost entirely on the medium — under a millikelvin in a stirred bath, tens of millikelvin in still air — so calibrate at a current and in a condition representative of use.Calibration
- Calibrating relative-humidity sensorsHumidity calibration is a temperature calibration in disguise. Relative humidity is a ratio against saturation, and saturation vapour pressure climbs about 6 % per degree — so half a degree of thermal disagreement between sensor and reference is worth more RH error than most people's whole budget.Calibration
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.
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. The engine is built and tested; the upload interface 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.
Next
Accounts, projects and dashboard
Authentication, tenant isolation and a customer workspace at app.valitrac.com.
Calibration workflow and certificates
DUT → method → equipment → reference → measurements → uncertainty → review → certificate.
Validation, monitoring and laboratory discovery
Qualification workflows, continuous monitoring and scope-backed laboratory search.
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.
How should a Pt100 be calibrated?
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]
Validated means every claim matched a source you can open. How answers are checked