Spectrophotometer calibration artifacts are commercially available from many sources. Each reference material artifact has a specified filter configuration, and each filter will have been “certified” with a specified scope of calibration. In a science-based Certificate or Report of Calibration, this vital information will be readily transparent in addition to the instrumental conditions used in the calibration procedure.
The recertification of spectrophotometer calibration artifacts, which is a very common practice of analytical UV/VIS spectrophotometric metrology, differs in many ways from the recertification of many other types of equipment in physical or engineering metrology. In fact, if the calibration laboratory has no prior knowledge or information about the most recent certification of the spectrophotometer calibration artifact in question, the quotation process will be complicated with the possible outcome of an irrelevant and incorrect quotation being issued.
The Certificate or Report of Calibration is usually the property of the owner of the spectrophotometer reference material artifact. When the time arrives to have a spectrophotometer reference material artifact recertified, the owner has at least two (2) different options in making the arrangements for the recertification:
(i) the owner works directly with the calibration laboratory – in this case, which is the most expedient and efficient, the owner can provide the Certificate or Report of calibration for the most recent certification directly to the calibration laboratory. This allows the quotation to be issued in the most timely manner – ideally within an hour or two.
(ii) the owner out-sources the recertification to a metrology management company that, in turn, works directly with the calibration laboratory – in this case, the owner must provide the Certificate or Report of calibration for the most recent certification directly to the metrology management company which in turn must then provide it to the calibration laboratory. The efficiency in issuance of the quotation obviously depends on the communication and UV/VIS metrological intuition between the owner and the metrology manangement company – common practice has shown that this can take anywhere from several hours to several days.
Therefore, it is clear, that the single most important document that simplifies the quotation process is the immediate availability of the certificate or report of calibration for the most recent certification for the reference material artifact that is intended for recertification. The previous certification measurement results are obviously required for immediate comparison to the “as found” measurement results to determine whether “adjustments” are required, that in turn, reflect upon the “as-left” measurements of the new certification.
