Agilent Technologies 34401A - Manual (Page 231)

Understanding the “ % of range ” Error The range error compensates
for inaccuracies that result from the function and range you select.
The range error contributes a constant error, expressed as a percent of
range, independent of the input signal level. The following table shows
the range error applied to the multimeter’s 24-hour dc voltage specification.
Total Measurement Error To compute the total measurement error,
add the reading error and range error. You can then convert the total
measurement error to a “percent of input” error or a “ppm (part-per-
million) of input” error as shown below.
% of input error =
Total Measurement Error
Input Signal Level
×
100
ppm of input error =
Total Measurement Error
Input Signal Level
×
1,000,000
Error Example Assume that a 5 Vdc signal is input to the multimeter on the 10 Vdc range.
Compute the total measurement error using the 90-day accuracy
specifications:
± (0.0020% of reading + 0.0005% of range).
Range
10 Vdc
10 Vdc
10 Vdc
Input Level
10 Vdc
1 Vdc
0.1 Vdc
Range Error
(% of range)
0.0004
0.0004
0.0004
Range
Error Voltage
≤ 40 µ V
≤ 40 µ V
≤ 40 µ V
Reading Error
Range Error
Total Error
= 0.0020% × 5 Vdc
= 0.0005% × 10 Vdc
= 100 µ V + 50 µ V
= 100 µ V
= 50 µ V
= ± 150 µ V
= ± 0.0030% of 5 Vdc
= ± 30 ppm of 5 Vdc
8
Chapter 8 Specifications
To Calculate Total Measurement Error
225