in circuits having distributed constants (G 01 R 21/09 takes precedence) [2]
21
/
08
•
by using galvanomagnetic-effect devices, e.g. Hall-effect devices (such devices per seH 01 L) [2]
21
/
09
•
•
in circuits having distributed constants [2]
21
/
10
•
by using square-law characteristics of circuit elements, e.g. diodes, to measure power absorbed by loads of known impedance (G 01 R 21/02 takes precedence) [2]
21
/
12
•
•
in circuits having distributed constants
21
/
127
•
by using pulse modulation (G 01 R 21/133 takes precedence) [4]
21
/
133
•
by using digital technique [4]
21
/
14
•
Compensating for temperature change [2]
22
/
00
Arrangements for measuring time integral of electric power or current, e.g. by electronic methods (electromechanical arrangements G 01 R 11/00; monitoring electric consumption of electrically-propelled vehicles B 60 L 3/00) [4]
Note
An arrangement for measuring time integral of electric power is classified in group G 01 R 21/00 if the essential characteristic is the measuring of electric power. [4]
22
/
02
•
by electrolytic methods [4]
22
/
04
•
by calorimetric methods [4]
23
/
00
Arrangements for measuring frequencies; Arrangements for analysing frequency spectra (frequency discriminators
H 03 D)
23
/
02
•
Arrangements for measuring frequency, e.g. pulse repetition rate; Arrangements for measuring period of current or voltage (measuring short time intervals G 04 F)
23
/
04
•
•
adapted for measuring in circuits having distributed constants
23
/
06
•
•
by converting frequency into an amplitude of current or voltage
23
/
07
•
•
•
using response of circuits tuned on resonance, e.g. grid-drip meter [2]
23
/
08
•
•
•
using response of circuits tuned off resonance
23
/
09
•
•
•
using analogue integrators, e.g. capacitors establishing a mean value by balance of input signals and defined discharge signals or leakage (radiation-measuring instruments in which pulses generated by a radiation detector are integrated G 01 T 1/15) [2]
23
/
10
•
•
by converting frequency into a train of pulses, which are then counted
23
/
12
•
•
by converting frequency into phase shift
23
/
14
•
•
by heterodyning; by beat-frequency comparison (generation of oscillations by beating unmodulated signals of different frequencies H 03 B 21/00) [2]
23
/
15
•
•
Indicating that frequency of pulses is either above or below a predetermined value or within or outside a predetermined range of values, by making use of non-linear or digital elements [3]
23
/
16
•
Spectrum analysis; Fourier analysis
23
/
163
•
•
adapted for measuring in circuits having distributed constants [3]
23
/
165
•
•
using filters [3]
23
/
167
•
•
•
with digital filters [3]
23
/
17
•
•
with optical auxiliary devices [3]
23
/
173
•
•
Wobbulating devices similar to swept panoramic receivers (panoramic receivers per seH 03 J 7/32) [3]
