Use of air buoyancy compensation factor – RADWAG MYA 5.3Y.F1 Microbalance User Manual

Page 24

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10.6. Use of air buoyancy compensation factor

The application enables correcting mass measurement errors during:

1. Weighing loads that density considerably differs from the density of

standard used to adjusting the balance. Regularly, the balance is adjusted

with a steel mass standard with density ~8.0g/cm

3

or a brass mass

standard with density ~8.7g/cm

3

. If loads made of other substances are

weighed, then ratio indicated on below chart should apply.

Below chart presents the value of mass correction in relation to the density

of weighed load, assuming that air density is constant and equals

1.2 kg/m

3

.

C

or

rec

tion

val

ue

[m

g]

D

ens

ity

of

w

ei

ghed

loa

d

Sample mass [g]

Error value in relation to density of weighed sample

1. Testing the changes of sample mass within a few hours’ time, if: sample

mass is relatively constant (minor changes). In such case it is assumed,

that considerable effect on the measurement result rests on air density

changes, which is affected by changes of pressure, temperature and

humidity.

In order to carry out a reliable measurement, apart from being familiar with

relations applying to ambient conditions, an operator should know the

measuring methods, features of tested sample, air density in the laboratory

room and density of weighed sample.

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