Each time I send my B & K 2250 sound level meter for calibration I am asked whether I want it to be done to the UK standard UKAS, or with traceability to the same standard. The latter is cheaper so I tend to use it. Is there likely to be a significant difference, and in what situation would you recommend paying for the more expensive service? Thanks.
The answer to your question mostly depends on what type of legal evidence of calibration you need for the work you are doing with your 2250. A traceable calibration can demonstrate that the equipment used to calibrate your 2250, can have its own calibration traced back to comparison measurements to a known standard at an NMI.
The UKAS calibration is an accredited calibration, that proves that the management and technical procedures, as well as traceability of measuring instruments, have been verified by an accreditation body (typically UKAS for a UK based laboratory). This is commonly required for legally relevant measurements, depending on the specific regulations for the work.
If you purchase an accredited sound level meter calibration from Brüel & Kjær/HBK, it will be performed in our DANAK accredited laboratory in Denmark. DANAK and UKAS accredited certificates are covered by a mutual recognition agreement - meaning that DANAK accredited certificates are recognized in the UK as equivalent to UKAS, and vice versa.