Precise colour measurement of rolled oats using statistical averaging on the Agera L2 colour measurement device is particularly useful for rolled oats, as they are among the samples that consist of various particles and have uneven colour distribution or surface texture. In any case, the samples should be measured at least two to five times, with rotation or refilling between measurements, so that a meaningful mean value can be formed. The standard deviation and range (scatter) can be read off for each individual measurement.
Table 1 shows the results of five individual measurements taken with the HunterLab Agera L2. For this purpose, oatmeal from a single batch was placed in a glass cuvette with a diameter of 6 cm, and the colour was measured through the bottom of the cuvette. Between measurements, the cuvette was emptied and refilled with samples from the same batch. The mean value was then calculated from these five measurements. The range (dispersion) and standard deviation of the values allow for an estimation of the variations in the measured values for these somewhat heterogeneous samples.
In Table 2, five (5) measurements were averaged to one value each during the measurement, thus reducing the scatter. Using the average of all five results, the colour of the batch is ultimately determined with great precision, as can be seen from the significantly lower values for the range and standard deviation.
Measuring from below through the bottom of the cuvette is particularly advantageous for small-grained samples or powders, as this produces a more uniform surface structure than when viewed from above. In addition, the Agera has a specially installed camera that can capture an image of the sample as it is “seen” by the sensor. An RGB histogram of the recording can also be displayed at the same time. This recording can be saved together with the measurement data.
However, other solutions are also possible, depending on the sample quantity, the processing and the environmental conditions. HunterLab offers non-contact colorimeters and online/inline measuring devices for this case. In any case, with HunterLab you are choosing the supplier with the highest quality spectrophotometers for the food industry on the market.