Abstract: One aspect of the invention is a method for determining whether systematic biases are present in an instrument. The method involves first obtaining a series of replicates produced by an instrument. Then, a Fourier Transform is performed on that data, thereby generating a secondary spectrum which indicates the frequency characteristics of the data. This secondary spectrum is then compared to secondary spectra obtained in a similar matter from a series of random number sets to determine whether variations observed are within an expected range as defined by the random number series.Another aspect of the invention is a method for determining an optimum frequency at which the instrument should be calibrated. This method comprises obtaining a set of multivariate data as before, and treating every xth data point as a calibration point and adjusting the values of the points following the calibration point accordingly. A Fourier Transform is then calculated as before.

Abstract: A technique for determining and distinguishing between specific species of chlorine in a supply of water is disclosed herein along with certain applicable apparatus. In carrying out this technique, one or more water samples are obtained from a larger supply and made to display a pH within a specific range. In a preferred embodiment, a sample is provided for each of the different species of chlorine to be determined. A predetermined amount of hydrogen peroxide is added to each of these samples. If hypochlorous acid and/or hypochlorite (one of the species to be determined) is present in any of the samples, the hydrogen peroxide by itself will react therewith for producing oxygen. If however either monochloramine or dichloramine (other chlorine species) is present, it is necessary to combine the hydrogen peroxide with a certain minimum amount of iodine, preferably in the form of potassium iodide, to produce an oxygen evolving reaction.

Abstract: A technique for determining and distinguishing between specific species of chlorine in a supply of water is disclosed herein along with certain applicable apparatus. In carrying out this technique, one or more water samples are obtained from a larger supply and made to display a pH within a specific range. In a preferred embodiment, a sample is provided for each of the different species of chlorine to be determined. A predetermined amount of hydrogen peroxide is added to each of these samples. If hypochlorous acid and/or hypochlorite (one of the species to be determined) is present in any of the samples, the hydrogen peroxide by itself will react therewith for producing oxygen. If however either monochloramine or dichloramine (other chlorine species) is present, it is necessary to combine the hydrogen peroxide with a certain minimum amount of iodine, preferably in the form of potassium iodide, to produce an oxygen evolving reaction.