Guide: NABL
NABL calibration records: what to keep, and what software is not
NABL is India's accreditation body for testing and calibration laboratories. A NABL symbol on a certificate means the lab is accredited for that work, not that your plant is. This page is what to file from that certificate so an auditor can follow the chain. The wider idea is in calibration traceability.
Key takeaways
- NABL accredits laboratories. It does not accredit your factory, and it does not accredit a CMMS.
- Keep the certificate itself, not a line in a spreadsheet that says "NABL done".
- The useful fields are the instrument identity, the results, the uncertainty, the due date and the traceability statement.
- An out-of-tolerance result needs an impact look at the product measured since the last good calibration.
- Store the certificate on the instrument's calibration record so the next auditor does not hunt a shared drive.
What NABL is, in plant language
When a gauge, a thermometer or a pressure transmitter is calibrated, someone compares it with a better reference and writes down the result. Traceability is the chain of those comparisons back to a national or international standard. Accreditation is how you know the laboratory doing the comparison is competent for that measurement.
In India, that accreditation body is NABL, the National Accreditation Board for Testing and Calibration Laboratories. NABL is a signatory to the ILAC arrangement, which is why a NABL certificate is recognised beyond India. The symbol belongs on the laboratory's certificate for the scope they hold. It does not belong on your maintenance software, and it does not mean every instrument in the plant is covered.
What to keep from the certificate
File the PDF. Also write these fields on the instrument record so you can filter overdue work without opening every file.
| Field | Why an auditor asks |
|---|---|
| Instrument identity: tag, serial number, range | So the certificate is this gauge, not one like it |
| Laboratory name and certificate number | So the certificate can be traced back to the lab |
| Whether the lab's scope covers this measurement | A NABL logo on an unrelated test does not cover your pressure gauge |
| As-found and as-left results, or the statement of compliance | So you know if it was already out when it arrived at the lab |
| Measurement uncertainty | A pass without uncertainty is a weaker claim. The lab states how large the doubt is |
| Traceability statement | Which reference the lab used, and that the chain continues upward |
| Date of calibration and the next due date your interval sets | The lab date is when they measured it. Your interval decides when it is due again |
| Who received it back and put it into use | So a gauge cannot return to the floor with nobody owning it |
When the result is out of tolerance
If the as-found result is outside the tolerance you use on the floor, quarantine the instrument and look at what it measured since the last known-good calibration. That impact review is your quality procedure: re-inspect, contain, or document why no product action is needed. Then repair or adjust, calibrate again, and decide whether the interval should be shorter.
The certificate is the evidence of the lab's result. The impact decision is yours. Keep both on the same instrument.
A simple filing rule
One instrument, one record, every certificate in date order. When a new certificate arrives, the previous one stays. Auditors ask what the gauge read last year as often as they ask whether it is in date today. A folder named "calibration" with two hundred PDFs and no tag numbers fails that question even when every lab did the work.
Match the tag on the gauge to the tag on the certificate before the gauge goes back into use. A certificate for a serial number you cannot find on the floor is not evidence for the gauge you are using. If the lab report covers several instruments, split the filing in your register so each tag points at its own result.
Review overdue instruments as a list, weekly, the same way you review overdue PMs. A certificate in a drawer does not tell you which gauge expired on Tuesday. When a gauge is taken out of service, say so on the record. An overdue calibration on a gauge that is in a cupboard is a different problem from an overdue calibration on a gauge that released product yesterday, and the list should show which is which.
If you use an outside lab and an in-house check, do not mix them up. An in-house verification against a working standard is not a NABL calibration unless an accredited lab performed it under their scope. Label the record with who did the work. Keep the lab's scope statement with the first certificate you file from that lab, so the next audit does not depend on someone's memory of what the logo covers.
What MaintenanceIQ stores, and what it is not
MaintenanceIQ schedules calibration for an asset or for an instrument fitted to it, and your team uploads the laboratory PDF to that calibration instance. You can record the vendor and that the calibration was NABL. The asset's calibration tab lists what is coming due and what is done. MaintenanceIQ does not generate NABL certificates, and it is not a NABL-accredited laboratory.
See calibration management software for how the schedule and the uploaded certificate sit on the asset.
Sources
- National Accreditation Board for Testing and Calibration Laboratories (opens in a new tab), NABL
- ILAC Mutual Recognition Arrangement (opens in a new tab), International Laboratory Accreditation Cooperation
Frequently asked questions
Is MaintenanceIQ NABL accredited?
No. NABL accredits laboratories. MaintenanceIQ records which lab calibrated an instrument, whether that calibration was NABL, and keeps the uploaded certificate as proof.
Is a sticker enough?
A sticker shows someone touched the instrument. The certificate shows the result, the uncertainty and the chain. Keep the certificate.
Who sets the next due date?
Your calibration interval does, often monthly, quarterly, half-yearly or yearly, based on the instrument and how it is used. The laboratory's certificate date is the start of that interval, not a replacement for it.
What if the lab is accredited but not for this test?
Then the NABL symbol does not cover the work. Check the laboratory's scope for the measurement you asked for, or ask the lab to state it on the certificate.