A technique known as the uniform blowing procedure is used to separate light-weight material such as chaff and empty florets from heavier seeds. To find the optimum blowing point of the seed blowers, the laboratory needs calibration samples of Poa species and Dactylis glomerata.
To maintain worldwide consistency of analysis, the International Seed Testing Association (ISTA) provides samples for calibration of blowers. These calibration samples, which are produced by DLF, are distributed through the ISTA Secretariat.