MICRO-EPSILON eddyNCDT SGS 4701, Руководство по эксплуатации

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Appendix| Target Thickness
eddyNCDT SGS 4701
A 5 Target Thickness
The principle of eddy current displacement measurement requires a minimum thickness for stable results.
This minimum thickness depends on the target material used and the sensor frequency.
The default system works at a carrier frequency of 1 MHz.
Skin depth [µm]
100
10
10 1
100
1000
0.1
2000
1.4005
Nickel
1.4301
Lead
Bronze
Brass
Magnesium
Aluminium
Gold
Copper
Silver
µ
r
=1
µ
r
=10
µ
r
=100
µ
r
=1000
µ
r
=10,000
Electrical conductivity [Mega Siemens / m]
2.4668
1.4571
3.4365
1.1141
Fig. 13 Skin depth at 1 MHz compared to electrical conductivity
i
When measuring the path at variable temperatures, the minimum target thickness is three times the skin
depth.