Screening arrangements against electric or magnetic fields, e.g. against earth's field
G01R 1/20
·
Modifications of basic electric elements for use in electric measuring instruments; Structural combinations of such elements with such instruments (instrument transformers per seFulltext... Hierarchy... Expanded...H01F 29/10)
G01R 1/22
· ·
Tong testers acting as secondary windings of current transformers
G01R 1/24
· ·
Transmission-line measuring sections, e.g. slotted section
G01R 1/26
· · ·
with linear movement of probe
G01R 1/28
·
Provision in measuring instruments for reference values, e.g. standard voltage, standard waveform
G01R 1/30
·
Structural combination of electric measuring instruments with basic electronic circuits, e.g. with amplifier
Circuits for inserting reference markers, e.g. for timing, for calibrating, for frequency marking
G01R 13/32
· · ·
Circuits for displaying non-recurrent functions such as transients; Circuits for triggering; Circuits for synchronisation; Circuits for time-base expansion
G01R 13/34
· · ·
Circuits for representing a single waveform by sampling, e.g. for very high frequencies
with indication of measured value by calibrated null indicator
G01R 19/00
Arrangements for measuring currents or voltages or for indicating presence or sign thereof (for measuring bio-electric currents or voltages Fulltext... Hierarchy... Expanded...A61B 5/04)
G01R 19/02
·
Measuring effective values, i.e. root-mean-square values
G01R 19/04
·
Measuring peak values non-sinusoidal waveforms
G01R 19/06
·
Measuring real component; Measuring reactive component
G01R 19/08
·
Measuring current density
G01R 19/10
·
Measuring sum, difference, or ratio
G01R 19/12
·
Measuring rate of change
G01R 19/14
·
Indicating direction of current; Indicating polarity of voltage
by using square-law characteristics of diodes, to measure power absorbed by loads of known impedance
G01R 21/12
· ·
in circuits having distributed constants
G01R 23/00
Arrangements for measuring frequencies; Arrangements for analysing frequency spectra (frequency discriminators Fulltext... Hierarchy... Expanded...H03D)
G01R 23/02
·
Arrangements for measuring frequency, e.g. pulse repetition rate; Arrangements for measuring period of current or voltage (measuring short time intervals Fulltext... Hierarchy... Expanded...G04F)
G01R 23/04
· ·
adapted for measuring in circuits having distributed constants
involving adjustment of a phase shifter to produce a predetermined phase difference, e.g. zero difference
G01R 25/06
·
employing quotient instrument
G01R 27/00
Arrangements for measuring resistance, reactance, impedance, or characteristics derived therefrom
G01R 27/02
·
Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant (by measuring phase angle only Fulltext... Hierarchy... Expanded...G01R 25/00)
G01R 27/04
· ·
in circuits having distributed constants
G01R 27/06
· · ·
Measuring reflection coefficients; Measuring standing-wave ratio
G01R 27/08
· ·
Measuring resistance by measuring both voltage and current
G01R 27/10
· · ·
using two-coil or crossed-coil instruments forming quotient
Measuring impedance of element or network through which a current is passing from another source, e.g. cable, power line
G01R 27/18
· · ·
Measuring resistance to earth
G01R 27/20
· ·
Measuring earth resistance; Measuring contact resistance of earth connections, e.g. plates
G01R 27/22
· ·
Measuring resistance of fluids
G01R 27/24
· · ·
Construction of measuring vessel; Electrodes therefor
G01R 27/26
· ·
Measuring inductance or capacitance; Measuring quality factor, e.g. by using the resonance method; Measuring loss factor; Measuring dielectric constants
G01R 27/28
·
Measuring attenuation, gain, phase shift, or derived characteristics of electric four-pole networks, i.e. two-port networks; Measuring transient response (in line transmission systems Fulltext... Hierarchy... Expanded...H04B 3/46)
G01R 27/30
· ·
with provision for recording characteristics, e.g. by plotting Nyquist diagram
Measuring form factor, i.e. quotient of root-mean-square value and arithmetic mean of instantaneous value; Measuring peak factor, i.e. quotient of maximum value and root-mean-square value