HP 34401A User Manual page 224

Chapter 8 Specifications
To Calculate Total Measurement Error
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.
Range
10 Vdc
10 Vdc
10 Vdc
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
ppm of input error =
Assume that a 5 Vdc signal is input to the multimeter on the 10 Vdc range.
Error Example
Compute the total measurement error using the 90-day accuracy
specifications:
Reading Error
Range Error
Total Error
Range Error
Input Level (% of range)
10 Vdc
0.0004
1 Vdc
0.0004
0.1 Vdc
0.0004
Total Measurement Error
=
Input Signal Level
Total Measurement Error
Input Signal Level
(0.0020% of reading + 0.0005% of range).
= 0.0020% 5 Vdc
= 0.0005% 10 Vdc
= 100 V + 50 V
Range
Error Voltage
40 V
40 V
40 V
100
1,000,000
= 100 V
= 50 V
= 150 V
= 0.0030% of 5 Vdc
= 30 ppm of 5 Vdc
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