To Calculate Total Measurement Error
Each specification includes correction factors which account for errors
present due to operational limitations of the internal
DMM
. This section
explains these errors and shows how to apply them to your measurements.
Refer to “Interpreting Internal DMM Specifications,” starting on page
28, 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 r % 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
µ
V
≤
15
µ
V
≤
1.5
µ
V
Chapter 1 Specifications
To Calculate Total Measurement Error
26
Summary of Contents for 34970A
Page 1: ...Agilent 34970A Data Acquisition Switch Unit Service Guide ...
Page 34: ...32 ...
Page 35: ...2 Quick Start 2 ...
Page 49: ...3 Front Panel Overview 3 ...
Page 62: ...60 ...
Page 63: ...4 Calibration Procedures 4 ...
Page 118: ...116 ...
Page 119: ...5 Theory of Operation 5 ...
Page 159: ...6 Service 6 ...
Page 177: ...General Disassembly 4 3 2 1 6 Chapter 6 Service Disassembly 175 ...
Page 178: ...Internal DMM Disassembly 3 2 1 Chapter 6 Service Disassembly 176 ...
Page 180: ...Additional Chassis Disassembly 1 2 Chapter 6 Service Disassembly 178 ...
Page 181: ...Plug In Module Disassembly Needle nose Pliers 6 Chapter 6 Service Disassembly 179 ...
Page 182: ...180 ...
Page 183: ...7 Replaceable Parts 7 ...
Page 220: ...Chapter 7 Replaceable Parts Manufacturer s List 218 ...
Page 221: ...8 Schematics 8 ...
Page 272: ......