A time division multiplexed measurement technique is used for spectral measurements in active wavelength division multiplexed loaded optical links, and offers instantaneous real-time correlation of performance and spectral parameters of the link, which is important for dynamic characterization of link performance during transient effects or polarization mode dispersion fluctuations. The data gathering system comprises a plurality of data gathering nodes and a control center. The testing process requirement data stored in association with the fuse ID of each of the devices is then accessed, and the devices are sorted in accordance with the accessed data into those devices requiring enhanced reliability testing and those requiring standard testing. To notify a particular user of changes that would be of interest to the user, a subset of the change records contained in the activities log is selected based on user-specific selection criteria. For each respective fluorescent measurement, the model comprises a respective equation for Nn, where Nn is the calculated amount of the target nucleic acid in cycle n of the corresponding PCR amplification experiment, and the equation for Nn is expressed in terms of K and N0, where K is the Michaelis-Menton constant. The device and method use ferromagnetic separation particles having a mean diameter of 100 to 250 \u03bcm located in a alternating magnetic field.