MetTutor Explorer — Free Metrology Education
Explorer · Free forever

Explore the science that measures everything

Curious about how the world is measured? You’re already a metrologist. MetTutor Explorer gives you real conversations with an AI tutor grounded in international metrology standards — no credit card, no time limit, no feature cliffs.

Start exploring → Compare all plans

Free forever · No credit card required

15,000+
Standards chunks
3
Learning modes
3
Built-in calculators
Free
Forever
What you get

A genuine feel for MetTutor’s capabilities

Explorer isn’t a limited trial — it’s a full AI tutor experience grounded in real standards. Learn concepts, solve problems, and practice for the CCT exam with answers you can trust.

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AI tutor powered by the MetLibrary
Every response is grounded in over 15,000 curated standards reference chunks spanning measurement science, calibration systems, quality management, and uncertainty analysis. Cited in APA format so you can verify every claim.
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Standards-grounded answers
Conversations are anchored in ISO/IEC 17025:2017 and NIST GUM (JCGM 100:2008) — the foundational standards for laboratory competence and measurement uncertainty. No hallucinations, no guesswork.
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Daily quiz — 3 questions per day
Test your metrology knowledge with three practice questions daily, covering topics from the ASQ CCT Body of Knowledge. A quick, focused way to build and maintain measurement science competency.
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Three built-in calculators
SI Unit Converter for dimensional analysis, significant figures calculator for data reporting, and a simplified TUR/TAR calculator for basic test uncertainty ratio evaluation — available to every Explorer.
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Speech input & read-aloud
Use microphone input to speak your questions and per-message read-aloud to listen to MetTutor’s responses. Full accessibility support across desktop and mobile browsers.
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Light & dark themes
Choose your preferred visual mode. MetTutor supports both light and dark themes across all plans, with 7-day conversation history to pick up where you left off.
Learning modes

Three ways to learn metrology

Every mode is powered by the MetLibrary. Choose how you want to engage — from foundational concepts to structured exam preparation.

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Concept
Explore metrology concepts — traceability, uncertainty, ISO 17025, units, and calibration principles — with standards-grounded explanations and APA citations.
Included
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Problems
Work through numerical problems step by step — uncertainty budgets, TUR calculations, unit conversions, and statistical analysis with guided solutions.
Included
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Exam Prep
Prepare for the ASQ Certified Calibration Technician exam with practice questions, explanations, and Body of Knowledge coverage review.
Included
📄 Document Navigator mode — structured exploration of metrology standards, ISO 17025 clauses, and NIST GUM sections — is available on the Professional plan and above.
Everything included

The complete Explorer feature list

Every feature below is available on the free Explorer plan — no upgrade required, no expiration, no credit card.

✓ AI tutor (MetLibrary RAG — 15,000+ chunks)
✓ Concept coach mode
✓ Problem solver mode
✓ Exam prep mode (CCT)
✓ ISO/IEC 17025:2017 grounded answers
✓ NIST GUM uncertainty fundamentals
✓ Daily quiz (3 questions per day)
✓ SI Unit Converter
✓ Significant figures calculator
✓ TUR/TAR calculator (simplified)
✓ Mic input (speech-to-text)
✓ Read-aloud per message (TTS)
✓ Light + dark themes
✓ 7-day conversation history
When you’re ready for more

Upgrade paths from Explorer

Explorer gives you a genuine feel for MetTutor. When you need unlimited quiz, certification prep tools, professional calculators, or team management — upgrade anytime.

Next step
Student
The complete learning engine for certification candidates and early-career technicians.
  • + Unlimited daily quiz
  • + CCT mock exam (125 questions)
  • + SM-2 spaced repetition
  • + Goal-paced review (exam date targeting)
  • + Mastery badges & achievements
  • + Study Achievement Record (PDF)
  • + Ad-free experience
See Student details →
Full platform
Professional
Everything in Student plus professional tools, document generation, and the full advanced standards corpus.
  • + GUM Uncertainty Budget calculator
  • + Gage R&R (ANOVA → CMC)
  • + Decision rules & guard banding
  • + Document generation (.docx, .xlsx, PDF)
  • + Saved conversations & Context Panel
  • + Document Navigator mode
  • + Full advanced standards corpus
See Professional details →
FAQ

Frequently asked questions

There’s no catch. Explorer is free forever — no credit card, no trial period, no expiration. You get a full AI tutor experience powered by the MetLibrary, three learning modes, daily quiz questions, and three built-in calculators. The only limitation compared to paid plans is that advanced tools like the GUM Uncertainty Budget, document generation, spaced repetition, and the full mock exam require a Student or Professional subscription.
Explorer has access to the core MetLibrary, which includes ISO/IEC 17025:2017, NIST GUM (JCGM 100:2008), NIST TN 1297, ASQ CCT Body of Knowledge, and VIM (JCGM 200:2012). The advanced standards corpus — including NCSLI Recommended Practices, ANSI/NCSL Z540.3, A2LA reference guides, and JCGM 106 decision rules — is available on Professional plans and above.
Yes. You can upgrade to Student or Professional at any time from your Account page, and upgrades take effect immediately. Your Explorer account and conversation history carry forward to the upgraded plan.
Each day you receive three quiz questions covering topics from the ASQ CCT Body of Knowledge. Questions come with explanations and standards references so you learn from each one. Student and Professional plans unlock unlimited daily quiz along with the full 125-question timed mock exam.
No. Document generation (Word, Excel, PDF export), the Context Panel workspace, saved conversations, and document upload are Professional-tier features. Explorer focuses on learning through conversation, quiz practice, and built-in calculators.

Start exploring metrology today

No credit card. No time limit. Just open MetTutor and start asking questions about measurement science.

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© 2026 AI Metrologist, LLC · MetTutor v3.0

NCSL International (NCSLI), the American Association for Laboratory Accreditation (A2LA), the American Society for Quality (ASQ), the American National Standards Institute (ANSI), the International Organization for Standardization (ISO), the International Electrotechnical Commission (IEC), the Joint Committee for Guides in Metrology (JCGM), and the National Institute of Standards and Technology (NIST) are trademarks or registered marks of their respective organizations. MetTutor is not affiliated with or endorsed by these organizations.