Biox offers a Passport Service that aims to return your instrument to as near new condition as possible. During the service we repeat all the checks and calibrations performed on new instruments and take remedial action where necessary.
Of course, you can perform your own checks, so there is an argument that a passport service may be unnecessary. Judge for yourself. Take a look at the tests we performed on your instrument when new, as listed in its Instrument Passport. Are you satisfied that your instrument would still pass those tests? Is the flux density calibration that you measure today still close to the current factory calibration?
We recommend a passport service be carried out annually, and before major studies where you may need independent proof of correct functioning. The passport service checks every aspect of performance, including all calibrations, speed of response and temperature sensitivity. On some older instruments we also retro-fit some hardware and firmware updates that bring performance up to modern standards.