Ohaus 311 CENT-O-GRAM BALANCE Manual - Manual (Page 5)

ZEROING THE BALANCE
Slide all poises to their respective zero positions. Turn dial to zero position. You
can now zero the balance by rotating the knurled balance compensator knob at
the left end of the beam until the pointer on the right lines up with zero. (Note
how quickly the magnetic damping brings the pointer to rest.)
Check the balance periodically since foreign material may accumulate on the
beam or pan and cause a slight change in the zero balance position of the
pointer. Whenever the balance is moved to a new location, the balance should
be checked and zeroed again, if necessary.
WEIGHING
Weighing is a very simple and rapid operation. Place the specimen on the pan of
the balance. Proceed as follows for the fastest method of weight determination.
Model 310
1. Move the 200 gram poise on the rear beam to the first notch which causes the
pointer to drop, then move it back one notch, causing the pointer to rise.
2. Repeat this procedure with the 100 gram poise.
3. Turn the knob slowly until the pointer is exactly centered on the zero indicator.
4. The weight of the specimen is the sum of the values of both poise positions,
the dial position and the vernier reading.
NOTE: With a little practice, you will become proficient in learning exactly how
fast to turn the dial to come exactly to balance position the first time.
Shortcut procedures may be used in instances where approximate weight of the
specimen is known, as follows:
For specimens less than 100 grams, omit step 1.
For specimens less than 10 grams, omit steps 1and 2.
Figure 7. Example of 146.74 Gram Reading.
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