The MLR calibration for styrene in 10 overhead samples resulted in an R2 of 0.999 with a standard error of 0.84% styrene. The predicted vs. actual plot for this model is shown in Figure 2. The styrene calibration for the simpler stream resulted in the same R2 and a standard error of 0.37%. The photometer was installed on-line with two side stream flow probes using fiber optic cables and the factory calibrations. The results of over three months of data for the overhead stream is shown in Figure 3 compared with laboratory values for grab samples using a gas chromatograph. The average difference is 0.6 with a standard deviation of 1.2. The simpler stream was sampled infrequently because the analyzer’s styrene values matched the GC values within experimental error.
Conclusion:
A ClearView db can provide real-time, online measurements of both streams with no system down-time, permitting greater column efficiency. For the example above ROI was achieved in less than 6 months.