Frequently asked questions

Calibration compares your instrument's readings with a reference standard and determines the deviation and measurement uncertainty: it produces a quantified result, recorded in a certificate. Verification then consists of deciding whether this deviation is acceptable relative to the tolerance you have set. The two are complementary: you calibrate, then declare the instrument compliant or not.

There is no single mandatory interval. It is up to the company to define and justify it, as ISO 9001 requires for monitoring and measuring resources. It depends on frequency of use, criticality of the measurement, the environment and the calibration history. One year is often used as a starting point, then adjusted based on results. We can help you set up and track this schedule.

It is a certificate issued by a laboratory accredited to ISO/IEC 17025, which attests to its technical competence. The results are traceable to national and international standards and are reported with their uncertainty. This type of certificate is recognized by ISO 9001 and IATF 16949 auditors. Our services are carried out with accredited partner laboratories.

Yes. Most of the instruments we supply can be delivered with an initial calibration performed by an accredited laboratory, along with the corresponding certificate. Just mention it in your quote request.

Areas covered include electrical (power supplies, LCR meters, energy and power), time and frequency, dimensional (calipers, micrometers, rules), force (force gauges, torque meters), flowmeters and thermo-hygrometers. We also offer testing services: XRF alloy analysis, X-ray inspection, 3D measurement, climatic testing and metallographic sectioning. See all our metrology services.

Lead time depends on the type of instrument, the measurement range and the laboratory involved. We state it in the quote and group your instruments together to minimize downtime.

Yes. We design, build and certify our special machines with CE marking: risk assessment, mechanical and electrical safety, electromagnetic compatibility and a complete technical file. Discover our special machines.

Yes. Our quality management system is certified to ISO 9001:2015 by RoyalCert (certificate no. 09156/NOR09U, valid until 12/28/2028). View the certificate and quality policy.

Yes. NTT is a training center approved by the Tunisian Ministry of Vocational Training and Employment: ISO 9001, IATF 16949, ISO/IEC 17025, EN 61340-5-1 (ESD), the IPC series, and metrology. See training and consulting.

Send your request via our contact form, by email to commercial@ntt-tn.com or by phone at +216 51 788 384. Specify the part number you need or describe your requirement: part, tolerance, quantity, lead time.