Baseline control charts

Set the sensitivity in the UV monitor control unit to a suitable value that will enable peak detection at a given concentration of protein Zero the baseline or chart recorder. 

If your deuterium lamp is old, it can be checked by the reading of the hours of operation. A critical limit is 800-1000 hours - in theory. However, it may well be that you can work very well after more than 1500-1800 hours. An old lamp can be detected by from the noisy baseline and small peaks, which should not be confused with spikes. Spikes are sharp lines due to air bubbles. Modern detectors contain a counter for lamp operation hours and also indicate the actual lamp energy. It should therefore be quite straightforward to identify an old lamp as the problem. Remember the control charts (see Tip No. 21). 

This chart was used by Dr. W. A. Shewhart for a continuing test of statistical significance.) A control chart is a chart with a baseline, frequently in time order, on which measurement or counts are represented by points that are connected by a straight line with an upper and lower limit. The control chart... 

The TRAACS 800+ is controlled by a personal computer and the features provided include complete interactive control via keyboard or mouse calculation of results as necessary taking into account baseline or sensitivity drift, graphical output of calibration curves for all calibration types—either Hnear or non-hnear, input facility for sample identification data allowing storage on disc and real-time results together with chart traces on a computer printer. The programs allow easy access to input or data files and connection to other computers, and gives system performance verification to CLP standards and built-in QC charts. 

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