The function of a spectrometer is to produce analyses. The fact that spectrometers consist of components such as an energy source and stand, optics, CCD, electronics and computer and that these in turn consist of sub-component and individual parts is often only of secondary interest to users. In a comparable way, a car-driver wants to drive a car and a television viewer wants to view television.

   If faults have occurred in a spectrometer which has been commissioned in good order, these faults must be removed. It is then necessary to test that overall operation of the spectrometer is satisfactory by measuring the RSD of the recalibration samples.

   If the user has not made a clear statement of defects, an effort must be made to specify them. A user unaccustomed to the terminology may understand “fluctuating” as meaning that:

1. Measurement accuracy on one and same sample is not good, that is, for individual or for all analytes;

2. Measurements on one and the same sample at different times do not agree.

3 . Spectrochemical analyses, in some cases or in all cases, do not agree with chemical analyses.

    There are different reasons for each of these three variants. What is good or bad requires clear definition.

    If no definite fault is reported, and no definite defect is found on the spectrometer, its efficiency must be tested in the form of the RSD, for which recalibration samples must be measured.

    If the actual values are found to be within the nominal values a stability test should be carried out . This long-term test should include a pause of 1h and the start and the end of a night.

    If the stability test result is within the nominal limits, the calibration must be checked with some check or reference samples. In so doing, so far as possible, samples should be used which were also used for the calibration.

    Note: Watch the RSD of reference for the corresponding base, namely at least one reference line for each optics system. The RSD should be 0.5-1%. A check on the BEC can also be useful.

    If these tests leads to detection of a defect and to work being done on the spectrometer the results of such servicing operations should subsequently be confirmed by measuring some recalibration samples. If these tests do not lead to detection of the fault, the user’s criticism usually relates to non-agreement between the spectrochemical and wet chemistry or other values. If it is a question of systematic differences, agreement can often be obtained, with the user’s content, by a small displacement of the recalibration HP. This should be noted in the service report and signed by the user.

    Under no circumstances should spectrometer- specific parameters such as the electrode gap, discharge parameters, pre-sparking and measurement times, interference equivalent etc. be altered. If this should prove necessary in special cases, separate analysis programmes should be established. Whenever the analysis range is to be altered or extended the operator who carried out commissioning should first be contacted.