Keysight Technologies U2741A, Руководство пользователя

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3 Measurement Tutorial
54 Keysight U2741A User’s Guide
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
Ω
) when
compared to Polytetrafluoroethylene (PTFE) insulators (10
13
Ω
). Leakage from
nylon or PVC insulators can easily contribute a 0.1% error when measuring a
1 M
Ω
resistance in humid conditions.
Table 3-2 Power dissipation for various resistance ranges
Range Test current DUT power at full scale
100 Ω 1 mA 100 mW
1 k
Ω
0.83 mA 689 mW
10 k Ω 100 mA 100 mW
100 k
Ω
10 mA 10 mW
1 M Ω 900 nA 810 nW
10 M
Ω
205 nA 420 nW
100 M Ω 205 nA || 10 M Ω 35 nW