Joyce Lee on mon 9 jun 03
On behalf of Louis Katz ....... j
More.
Old or abused scales can have the following problems.
1. Corroded or dulled knife edges. These are little triangular pieces=20
of metal that protrude from the beam assembly. They rest in plastic=20
"Bearings".
2. The bearings are easily replacable and cheap. The bearings go bad.
3. Worn weights. This happens when the scale has seen a lot of use in=20
dirty abrasive conditions. The 10 gm and hundreds weights no longer sit=20
in their holes. They can be replaced or exhnged with another scale, but=20
I doubt its wort the effort as when this has happend so usually has #4
4. Worn beams. Same reason and symptoms as #3.
5. Counterwieght hanging point out of balance.
Step 1. Clean your scale. Weigh your 500 gm. counterweight and compare=20
to the "actual weight " listed on the counterweight. it should match.
Step 2. put 500 grams of material on the scale. weigh it with the=20
sliding weights.
Step 3. now weight it with the counter weight. If the counter weight=20
side is low loosen the locknut on the couterweight hanger and and screw=20
the hanger into the scale body. If it is high, screw it out. Lock the=20
lock nut and recheck.
With good bearings and no wind your scale should be able to accurately=20
measure 1 gram within 5%. Its accuracy below 1 gram is much less.
Ohaus does sell scales for weighing smaller amounts. These are good for=20
small glaze tests and medium size tests with powerful colorants like=20
cobalt.
Louis
| |
|
