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Accuracy of formula preparation equipment for liquid measurement

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ABSTRACT

Background: Modular specialist feeds may consist of a number of individual liquid ingredients. Accurate feed preparation is dependent on competent liquid measurement. We investigate the accuracy of two measuring jugs (one retail mix-and-measure; and one produced to laboratory standards); and the influence of volume and technique on accuracy.

Materials and methods: 20 health professionals aged 18–60 y (mean: 46 y) measured 3 different volumes of water with each of two measuring jugs. For each volume with each jug, 2 measurements in randomised order were made: 1) eye-level with the jug, and 2) standing upright (total of 12 measurements). Measured quantities were weighed and the difference between measured and target volumes calculated.

Results: The laboratory jug was more accurate (mean difference 9.3 ml, range − 30.5 to 57.5 ml, std error mean 1.59) than the retail jug (mean difference − 17.7 ml, range − 92.0 to 48.5 ml, std error mean 1.59). Accuracy improved with increased volume (450 ml: mean difference − 9.4 ml, range − 75.5 to 49.5 ml, std error mean 1.95; and 810 ml: mean difference − 0.7 ml; range − 92.0 to 43.0 ml, std error mean 1.95).

Conclusions: Accurate measurement of liquid ingredients is difficult to achieve even for trained professionals. The cumulative effect of many different liquid measurement errors (inappropriate jug type, inaccurate volume measured and poor technique) may lead to clinically important errors in the preparation of modular specialist feeds.

No MeSH data available.


Variability of results for jug L and jug RMM for all eye level measurements (n = 20). Footnote: boxes = first to third quartile; line = second quartile (median); whiskers = minimum and maximum of all data.
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f0020: Variability of results for jug L and jug RMM for all eye level measurements (n = 20). Footnote: boxes = first to third quartile; line = second quartile (median); whiskers = minimum and maximum of all data.

Mentions: Each jug of the same type was used by between 3 and 10 participants for each of the measurements. A comparison of the results for each jug type (Jug L1, L2, L3; Jug RRM1, RMM2, RMM3) showed that there was significant variability between jugs of the same type (p < 0.0001; ANOVA) (Table 2; Fig. 3, Fig. 4). No two jugs of the same type measured exactly the same, although Jug RMM did consistently measure less than expected and Jug L more than expected but the latter was also consistently more accurate and more precise.


Accuracy of formula preparation equipment for liquid measurement
Variability of results for jug L and jug RMM for all eye level measurements (n = 20). Footnote: boxes = first to third quartile; line = second quartile (median); whiskers = minimum and maximum of all data.
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5121309&req=5

f0020: Variability of results for jug L and jug RMM for all eye level measurements (n = 20). Footnote: boxes = first to third quartile; line = second quartile (median); whiskers = minimum and maximum of all data.
Mentions: Each jug of the same type was used by between 3 and 10 participants for each of the measurements. A comparison of the results for each jug type (Jug L1, L2, L3; Jug RRM1, RMM2, RMM3) showed that there was significant variability between jugs of the same type (p < 0.0001; ANOVA) (Table 2; Fig. 3, Fig. 4). No two jugs of the same type measured exactly the same, although Jug RMM did consistently measure less than expected and Jug L more than expected but the latter was also consistently more accurate and more precise.

View Article: PubMed Central - PubMed

ABSTRACT

Background: Modular specialist feeds may consist of a number of individual liquid ingredients. Accurate feed preparation is dependent on competent liquid measurement. We investigate the accuracy of two measuring jugs (one retail mix-and-measure; and one produced to laboratory standards); and the influence of volume and technique on accuracy.

Materials and methods: 20 health professionals aged 18&ndash;60&nbsp;y (mean: 46&nbsp;y) measured 3 different volumes of water with each of two measuring jugs. For each volume with each jug, 2 measurements in randomised order were made: 1) eye-level with the jug, and 2) standing upright (total of 12 measurements). Measured quantities were weighed and the difference between measured and target volumes calculated.

Results: The laboratory jug was more accurate (mean difference 9.3&nbsp;ml, range &minus;&nbsp;30.5 to 57.5&nbsp;ml, std error mean 1.59) than the retail jug (mean difference &minus;&nbsp;17.7&nbsp;ml, range &minus;&nbsp;92.0 to 48.5&nbsp;ml, std error mean 1.59). Accuracy improved with increased volume (450&nbsp;ml: mean difference &minus;&nbsp;9.4&nbsp;ml, range &minus;&nbsp;75.5 to 49.5&nbsp;ml, std error mean 1.95; and 810&nbsp;ml: mean difference &minus;&nbsp;0.7&nbsp;ml; range &minus;&nbsp;92.0 to 43.0&nbsp;ml, std error mean 1.95).

Conclusions: Accurate measurement of liquid ingredients is difficult to achieve even for trained professionals. The cumulative effect of many different liquid measurement errors (inappropriate jug type, inaccurate volume measured and poor technique) may lead to clinically important errors in the preparation of modular specialist feeds.

No MeSH data available.