A&D BM-252 - Repeatability Test

BM series 33
6.7. Repeatability Test
Repeatability is an index of variation when measuring the same mass repeatedly.
Standard deviation is generally used for the indicator of repeatability.
The repeatability test measures the internal mass 10 times and displays the standard deviation.
Use the repeatability test function to inspect the performance of the balance when changing the
environment or when moving the balance to a new location.
Example: "Standard deviation = 0.2 mg" means that a probability of weighing errors being within
±0.2 mg is approx. 68% when measuring the same mass repeatedly.
Notes
When the password function is used, the repeatability test function is available only when
logged in as an administrator ( ).
The repeatability test uses the internal mass. Therefore, the obtained standard deviation
may disagree with that of the repeatability of "20. Specifications". Regard the standard
deviation as a reference.
Model 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 (for approx. 4 seconds)
until rep te5t is displayed, and then release
the key.
2 When rep te5t is displayed, the measurement
is automatically started, "r"e"p blinks and the
measurement count (0 to 10) is displayed.
To cancel 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 the weighing mode.
Press and hold
(approx. 4 seconds)
Release
In measuremen
t
Cancel
o
r
Resul
t
Standard deviation
C
oun
t
e
r
Example of BM-20
Weighing mode
Weighing mode