Using the Balance As A Direct Reading Balance

Mass Measurements
Page Navigation
30

Observation Number

Load

Balance Indication kg

B (std)

2,268.445

2,268.449

A+M

2,268.549

B+M

2,268.546

(3) The value for the unknown (A) may be calculated from the following formula.

Where the proportionality constant is

And M is the sensitivity weight. (M = 0.100)

A = 2,267.954 grams. (5 lb + .0035 grams)

Between each measurement, the beam should be arrested and either the sensitivity

NOTE: weight or the weight on the pan changed. A note should be taken of the sensitivity

weights used, so that they can be repeated for each double substitution.

5. Using the Balance As A Direct Reading Balance.

a. The Jupiter J5000S can be used as a conventional direct reading balance by means of

the following steps:

b. Set all the dials to read zero. Release the beam with the pan empty and depress the

ZERO button when the beam is in equilibrium. Arrest the beam.

c. Place the unknown sample on the pan. Turn the beam arrest to RELEASE (counter-

clockwise).

d. The display will indicate (-OVER) indicating that the dials have to be rotated to

increase weight indication. ARREST THE BEAM. Beginning with the 1 kg weight knob,

rotate to increasing numbers, releasing and arresting between changes, until the display

goes to (-UNDER). Turn the knob back to one lower digit (the indication will now be (-

OVER) again. Arrest the beam between each trial. Allow enough time after each trial to

be sure that the proper indication is observed.

e. Proceed to the next dial smaller and again begin increasing the reading on this dial

until an (-UNDER) reading is obtained. Reduce the indication by one digit and proceed

again to the next smaller knobs in the same fashion.

f. When operating the 10 g and 1 g knobs, the beam may be left in the released position.

g. When the indicator reads .XXX-IN RANGE, re-arrest the beam momentarily and

release again. Read the weight directly on the indicator.