Agilent Technologies 34420A, User Manual

Page: 283 / 294

Ratio Error
Example This example demonstrates how to compute the total measurement error
when using the Ratio Function. Assume a ratio measurement is made
with the following conditions:
•
Channel 1 , 5 V input on the 10 Volt range
•
Channel 2 , 10 mV input on the 10 mV range
To compute the total measurement error using the 90-day accuracy
specifications:
Ratio Error % = Channel 1 accuracy in % + Channel 2 accuracy in %
Channel 1 Reading Error %
=
0.0020%
Channel 1 Range Error %
=
0.0004%
∗
Range
Rea ding
=
.0004%
∗
10
5
=
.0008%
Total Channel 1 Error %
=
0.0020%
+
0.0008%
=
.0028%
Channel 2 Reading Error %
=
0.0040%
Channel 2 Range Error %
=
0.0002%
∗
Range
Reading
=
.0002%
∗
10 mV
10 mV
=
.0002%
Total Channel 2 Error %
=
0.0040%
+
0.0002%
=
.0042%
Ratio Error %
=
0.0028%
+
0.0042%
=
.0070%
Ratio
=
5 V
10 mV
=
500
±
0.0070%
=
500
±
0.035
For Ratio Measurements, if both input channels use the same range, use
0 for the % of reading error.
Chapter 8
To Calculate Total Measurement Error
284