Technical data

Specifications 2
34980A Service Guide 37
To Calculate Total DMM Measurement Error
Each specification includes correction factors which account for errors
present due to operational limitations of the optional internal DMM. 
This section explains these errors and shows how to apply them to your
measurements.
Refer to “Interpreting Internal DMM Specifications" on page 39, to get a
better understanding of the terminology used and to help you interpret the
internal DMM’s specifications.
The internal DMM’s accuracy specifications are expressed in the form:
(% of reading + % of range).
In addition to the reading error and range error, you may need to add
additional errors for certain operating conditions. Check the list below 
to make sure you include all measurement errors for a given function.
Also, make sure you apply the conditions as described in the footnotes 
on the specification pages.
• If you are operating the internal DMM outside the 23 °C ± 5 °C
temperature range specified, apply an additional temperature 
coefficient error.
• For dc voltage, dc current, and resistance measurements, you may need
to apply an additional reading speed error.
• For ac voltage and ac current measurements, you may need to apply an
additional low frequency error or crest factor error.
Understanding the “% of reading“ Error The reading error compensates
for inaccuracies that result from the function and range you select, as well
as the input signal level. The reading error varies according to the input
level on the selected range. This error is expressed in percent of reading. 
The following table shows the reading error applied to the internal DMM’s
24- hour dc voltage specification.
Range Input Level Reading Error
(% of reading)
Reading Error
Voltage
10 Vdc
10 Vdc
10 Vdc
10 Vdc
1 Vdc
0.1 Vdc
0.0015
0.0015
0.0015
150 V
15V
1.5 V