Specifications

Chapter 3: General Considerations
Industry Standards
(12/99) 3-15
Class III
4000d
2000d
500d 10,000d
-2.5
-2.0
-1.5
-1.0
-0.5
+2.5
+2.0
+1.5
+1.0
+0.5
0
Number
of
Divisions
Figure 3-8: OIML Acceptance Tolerance Table
Class III
4000d2000d500d 10,000d
-2.5
-2.0
-1.5
-1.0
-0.5
+2.5
+2.0
+1.5
+1.0
+0.5
0
Number
of
Divisions
OIML
Handbook 44
Handbook 44 & OIML
Figure 3-9: Handbook-44/OIML Acceptance Tolerance Overlay
In order be classified as "Legal for Trade," a scale must meet OIML acceptance
tolerances. The scale’s weight readings must be within the specified limits, relative to the
number of divisions (or increments) that correspond to the actual weight used. For
example, if a weight that corresponds to 5,000 divisions is placed on the scale, then the
indicator must display 5,000 divisions ±1.5 divisions in order to meet OIML acceptance
tolerances. In order for the same scale to meet NIST acceptance tolerances, the indicator
could display 5,000 divisions ±2.5 divisions. The wider acceptance tolerance allowed
by NIST was originally intended to approximate the 0.1% of applied load method.