Appendix 1 Precautions for Making Custom Test Leads
A2
• Do not allow the test leads near metal surfaces. In particular, the lead por-
tions that are not twisted together must be kept away from conductors to
avoid unstable measurements resulting from the effects of induced current.
See "Appendix 6 Effect of Eddy Currents" (p.A8).
• Observe the precautions illustrated in the following diagram concerning the
shape and placement of measurement leads. Eddy currents and outside
induced noise caused by nearby metallic objects can introduce an error
component or variation into measured values, degrading repeatability.
(The impact of these phenomena can be reduced as described below.)
• Use the minimum necessary wire length (5 m or less). Longer wire runs
are more susceptible to noise and may result in unstable measured values.
The sum of the round-trip wiring resistance and measurement lead contact
resistance should be 20
(for 3 m and 30 m ranges, 2 ) or less.
• Perform zero-adjustment prior to starting measurement. Make a zero-
adjustment jig and perform the process using the same configuration
(probe shape and placement) as will be used for actual measurement.
Nearby metallic objects may introduce an error component (offset) to mea-
sured values due to the effects of eddy currents and other phenomena.
This error component can be eliminated by performing zero-adjustment
after measuring the ideal zero resistance state (using the zero-adjustment
jig) for the same probe shape and placement that will be used to perform
actual measurement. This is particularly important when using the 3 m
and 30 m ranges, where the effects of eddy currents are more pro-
nounced.
• Avoid the use of metal plates (short bars) as a zero-adjustment jig as the
plate's resistance value will introduce an error component.
Do not place near a metal
plate or frame.
Metallic frame
Probe pins
Use the same probe pin contact position
for all measurements.
Source H
Sense H
Sense L
Source Ｌ
Positive terminal
・Minimize loop area
・Use the same loop shape and wire placement (including
distance from metallic parts on nearby equipment) for all
measurements.
Battery being measured
Negative terminal
×
Do not place metallic parts (device frames, etc.)
near the following objects:
・The vicinity of probe pins
・Cables (especially forked loops)
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