# NIST HDBK 44 Table T.3. Class III Tolerance in Divisions Clarification

#### dgriffith

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Table T.3. Class III Tolerance in Divisions (e), page 2-76, 2007 edition:
This is the applied mass load, but scaled in divisions instead of mass value?
Could someone help on this?

#### dwperron

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Try checking Table 3, Note 4 on page 2-14 for an explanation:

The number of scale divisions, n, for each weighing range is determined by dividing the scale capacity for each range by the verification scale division, e, for each range.

#### dgriffith

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Thanks for the response, and sorry, I should have been more clear.
I understand the divisions 'd' and 'e', but need to know what that first column header is referring to.
I interpret it to mean the test load is not in mass value (100 lbs, 50 kg, etc.), but in the number of divisions that mass load represents, which defines the tolerance in divisions, i.e. 500 lb scale @ 10,000 'e' divs yields a 0.05 division. A 500 lb test mass would represent 10,000 divisions, therefore the 4th line would indicate a tolerance of 5 divisions (0.25 lb) because the mass load is greater than 4001+ divisions.
Is that right or not, and if not, why.

#### dwperron

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I believe you have it right.
That's the way I have interpreted the standard for determining tolerances on scales.

#### dgriffith

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So, having established that the division "e" is 0.05 (500 lb FS and 10,000 division counts), if I then apply 150 lbs, do I do this?:
150 lb x 0.05 div/lb = 3000 div; the table 3rd line is 2000 - 4000 divisons, at that row the maintenance tolerance says now ?3 divisions.
Applying 150 lbs, the tolerance at that weight is ?3 div x 0.05 lbs/div = ?0.15 lbs.?
It seems to be a percentage of applied weight(reading).