TB 9-6670-254-50
a. Performance Check
NOTE
Balances (A1 or A3) are to be used for the single transposition
method.
(1) Place TI weight on left pan of appropriate double pan balance.
(2) Place standard weight of same nominal value (from appropriate weight set) (A5
through A11) on right pan of balance
NOTE
Several smaller weights may be summed to make up the
standard.
(3) Observe oscillations.
Record five turning points of balance pointer, using
worksheet similar to table 9.
Load
Turning points
Observation
(5 points)
number
Left pan
Right pan
RLRLR
(01) A-B
A (TI)
B (Std)
---
(02) B-A
B
A
---
(03) B + M-A
B+M
A
---
(04) A+M-B1
A+M
B
---
1When
necessary, an additional check (04) which makes up the double transposition method, may be used, resulting in the
following formula:
A = B + K (01 - 02 04 - 03)
4
NOTE
The recorded value for each turning point may be estimated in
tenths of smallest division. Oscillations to left of center are
used in calculations with a minus (-) sign and oscillations to
right of center are used with a plus +) sign.
(4) Transpose TI and standard weights and repeat (3) above.
(5) Select sensitivity weight of value large enough to be significant in weighing
procedure but small enough that balance pointer will remain on scale when it is added to
balance
