G01R29/00
Arrangements for measuring or indicating electric quantities not covered by groups G01R19/00 - G01R27/00
G01R29/00
Arrangements for measuring or indicating electric quantities not covered by groups G01R19/00 - G01R27/00
G01R29/12
Measuring electrostatic fields; or voltage-potential
G01R29/12
Measuring electrostatic fields; or voltage-potential