Linearity Error; Combining The Error Types - Fluke 5700A Series II Operator's Manual

5700A/5720A Series II
Operators Manual

4-46. Linearity Error

Linearity error occurs when the response curve of a meter deviates from a straight line.
This type of error is measured by fixing zero and near-full-scale endpoints on the
response curve, drawing a line through the points, then measuring how far the meter
response deviates from the straight line at various points. The error value is computed
relative to the selected full-scale point. The formula for linearity error is:
Where the "nominal setting" is calculated by subtracting the offset error and a
proportional part of the scale error.
Figure 4-9 illustrates linearity error with both offset and scale errors assumed to be zero.
The formula for linearity error yields:
CALIBRATOR
SETTING
LINEARITY
ERROR =
+7 mV

4-47. Combining the Error Types

The actual error of a meter is the combination of all three types of errors. The calibrator
uses o and S to allow you to separately display all three types of errors directly,
without having to do any calculation.
4-44
(Nominal setting) - (Adjusted 5720A setting)

Linearity Error =

Linearity Error =
19.9V
10.0V
9.993V
0
METER READING
Figure 4-9. Linearity Error
(Nominal full scale)
−
10 0 9 993 . .
= 0.000352 =+0.0352%
19 9 .
LINEAR RESPONSE
ACTUAL
RESPONSE
10.0V
19.9V