What are NIST (National Institute of Standards and Technology) traceable standards?

NIST traceable calibration certifies that the lab or manufacturer in question is equipped and able to calibrate equipment to National Institute of Standards and Technology (NIST) standards and that products by that manufacturer match NIST-maintained measurement standards. With NIST traceable calibration, any measurements taken with a certified instrument have an unbroken chain of measurement leading back to NIST-maintained standards with known and documented uncertainties for each step in the chain and a quality assurance program in place to address them.