A&D Weighing BM-20 - Manual (Page 30)

28 BM series
6.7.
Repeatability Test
The repeatability means the weighing error when measuring the same mass repeatedly.
The standard deviation is generally used for the indicator of the repeatability.
The repeatability test measures the built -in mass 10 times and displays the standard deviation.
Use the repeatability test to inspect the performance of the balance when changing environment
or when moving the balance to a new location.
Example: "The standard deviation = 0.2 mg" means that the probability of weighing error within
±0.2 mg is approx. 68% when measuring the same mass repeatedly.
Note
The repeatability test uses the internal mass. Therefore, the standard deviation discords to item
repeatability of " 17.Specifications". Regard the standard deviation as a reference.
Products Internal
mass
BM-20, BM-22 Approx. 20 g
BM-252, BM-500, BM-300, BM-200 Approx. 190 g
1 Press and hold the
RANGE key,
Release the key when displaying rep te5t .
2 When
displaying rep te5t , the measurement
is automatically started, "r"e"p blinks and the
measurement count (0 to 10) is displayed.
When stopping the current measurement,
press the
CAL key.
Note
Avoid vibration and breezes for precise
measurement during this test.
3 At the end of the measurement,
the standard deviation of the
repeatability is displayed.
4 Press
the CAL key or PRINT key
to return to weighing mode.
Press and hold
Release
In measurement
Stop
or
Result
The standard deviation
Counter
Example of BM-20
Weighing mode
Weighing mode