Errors in High Resistance Measurements
When you are measuring large resistances, significant errors can occur
due to insulation resistance and surface cleanliness. You should take
the necessary precautions to maintain a “clean” high-resistance system.
Test leads and fixtures are susceptible to leakage due to moisture
absorption in insulating materials and “dirty” surface films. Nylon and
PVC
are relatively poor insulators (10
9
ohms) when compared to
PTFE
Teflon
insulators (10
13
ohms). Leakage from nylon or
PVC
insulators
can easily contribute a 0.1% error when measuring a 1 M
Ω
resistance in
humid conditions.
DC Current Measurement Errors
When you connect the multimeter in series with a test circuit to
measure current, a measurement error is introduced. The error is
caused by the multimeter’s series
burden voltage
. A voltage is developed
across the wiring resistance and current shunt resistance of the
multimeter as shown below.
Teflon is a registered trademark of E.I. duPont deNemours and Co.
Ideal
Meter
V
s
I
LO
R
s
R
V
b
V
s
= source voltage
R
s
= DUT source resistance
V
b
= multimeter burden voltage
R = multimeter current shunt
Error
(
%
)
=
−
100%
x
V
b
V
s
7
Chapter 7 Measurement Tutorial
Errors in High Resistance Measurements
205
Содержание 34401A
Страница 12: ...1 Quick Start 1 ...
Страница 26: ...2 Front Panel Menu Operation 2 ...
Страница 50: ...3 Features and Functions 3 ...
Страница 103: ...4 Remote Interface Reference 4 ...
Страница 135: ...SCPI Status System 4 Chapter 4 Remote Interface Reference The SCPI Status Model 135 ...
Страница 170: ...5 Error Messages 5 ...
Страница 182: ...6 Application Programs 6 ...
Страница 196: ...7 Measurement Tutorial 7 ...
Страница 214: ...8 Specifications 8 ...
Страница 222: ...Product Dimensions TOP Product Dimensions All dimensions are shown in millimeters 8 Chapter 8 Specifications 223 ...