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Field evaluation of mechanical milk sampling devices on road tankers
Author(s) -
FLEMING M G
Publication year - 1988
Publication title -
international journal of dairy technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.061
H-Index - 53
eISSN - 1471-0307
pISSN - 1364-727X
DOI - 10.1111/j.1471-0307.1988.tb00581.x
Subject(s) - sampling (signal processing) , statistics , significant difference , sample size determination , sample (material) , environmental science , mathematics , standard deviation , zoology , sampling design , engineering , biology , chemistry , medicine , chromatography , electrical engineering , filter (signal processing) , population , environmental health
Six tanker‐mounted milk sampling devices (called ‘samplers’) were evaluated by comparing the samples taken by them with those taken manually from the same milk supplies by trained operators. The samplers under test, although of different design, transferred the milk from the tanker milk line directly to the sample bottle at a point near the milk pump. The sampling rate was adjusted before each operation to ensure a fixed sampling rate from the complete supply and provide a standard sample size. When sampling for compositional quality (per cent fat) from refrigerated farm bulk milk tanks the mean difference (bias) between sampler and manual control values ranged from 0.003 to 0.018, while the standard deviation of individual differences (sampler ‐ control) ranged from 0.043 to 0.088. When sampling for hygienic quality the mean difference (bias) between sampler and control samples for the standard plate count (expressed as log 10 ) ranged from 0.026 to 0.39, while the SD of individual differences ranged from 0.11 to 0.49. It is concluded that with correct installation and operation the sampling devices tested are satisfactory for sampling producer milk supplies for compositional quality but not all are suited for sampling for hygienic quality. However, with minor adjustment in design or operation, in some cases performance may be improved.