Arrangements for measuring phase angle between a voltage and a current or between voltages or currents (measuring power factor G 01 R 21/00; measuring position of individual pulses in a pulse train G 01 R 29/02; phase discriminators H 03 D) [2]
25
/
02
•
in circuits having distributed constants
25
/
04
•
involving adjustment of a phase shifter to produce a predetermined phase difference, e.g. zero difference
25
/
06
•
employing quotient instrument
25
/
08
•
by counting of standard pulses (measuring time intervals G 04 F) [2]
27
/
00
Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
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 G 01 R 25/00)
27
/
04
•
•
in circuits having distributed constants
27
/
06
•
•
•
Measuring reflection coefficients; Measuring standing-wave ratio
27
/
08
•
•
Measuring resistance by measuring both voltage and current
27
/
10
•
•
•
using two-coil or crossed-coil instruments forming quotient
27
/
12
•
•
•
•
using hand generators, e.g. meggers
27
/
14
•
•
Measuring resistance by measuring current or voltage obtained from a reference source (G 01 R 27/16, G 01 R 27/20, G 01 R 27/22 take precedence)
27
/
16
•
•
Measuring impedance of element or network through which a current is passing from another source, e.g. cable, power line
27
/
18
•
•
•
Measuring resistance to earth
27
/
20
•
•
Measuring earth resistance; Measuring contact resistance of earth connections, e.g. plates
27
/
22
•
•
Measuring resistance of fluids (measuring vessels, electrodes therefor G 01 N 27/07)
27
/
26
•
•
Measuring inductance or capacitance; Measuring quality factor, e.g. by using the resonance method; Measuring loss factor; Measuring dielectric constants
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
H 04 B 3/46)
27
/
30
•
•
with provision for recording characteristics, e.g. by plotting Nyquist diagram
27
/
32
•
•
in circuits having distributed constants [2]
29
/
00
Arrangements for measuring or indicating electric quantities not covered by groups G 01 R 19/00 to G 01 R 27/00
29
/
02
•
Measuring characteristics of individual pulses, e.g. deviation from pulse flatness, rise time, duration (of amplitude G 01 R 19/00; of repetition rate G 01 R 23/00; of phase difference of two cyclic pulse trains G 01 R 25/00; monitoring pattern of pulse trains
H 03 K 5/19) [3]
29
/
027
•
•
Indicating that a pulse characteristic is either above or below a predetermined value or within or beyond a predetermined range of values [3]
29
/
033
•
•
•
giving an indication of the number of times this occurs [3]
29
/
04
•
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
29
/
06
•
Measuring depth of modulation
29
/
08
•
Measuring electromagnetic field characteristics
29
/
10
•
•
Radiation diagrams of aerials
29
/
12
•
Measuring electrostatic fields
29
/
14
•
•
Measuring field distribution
29
/
16
•
Measuring asymmetry of polyphase networks
29
/
18
•
Indicating phase sequence; Indicating synchronism
29
/
20
•
Measuring number of turns; Measuring transformation ratio or coupling factor of windings (calibrating instrument transformers
G 01 R 35/02)
29
/
22
•
Measuring piezo-electric properties
29
/
24
•
Arrangements for measuring quantities of charge (electrostatic instruments G 01 R 5/28; indicating presence of current
G 01 R 19/15; electrolytic meters, calorimetric meters, for measuring time integral of electric current G 01 R 22/02, G 01 R 22/04) [2]
29
/
26
•
Measuring noise figure; Measuring signal-to-noise ratio [2]
