using diffraction elements, e.g. grating (gratings per seG 02 B)
3
/
20
•
•
•
Rowland circle spectrometers
3
/
22
•
•
•
Littrow mirror spectrometers
3
/
24
•
•
•
using gratings profiled to favour a specific order
3
/
26
•
•
using multiple reflection, e.g. Fabry-Perot interferometer, variable interference filter
3
/
28
•
Investigating the spectrum (using colour filters G 01 J 3/51) [4]
3
/
30
•
•
Measuring the intensity of spectral lines directly on the spectrum itself (G 01 J 3/42, G 01 J 3/44 take precedence)
3
/
32
•
•
•
Investigating bands of a spectrum in sequence by a single detector
3
/
36
•
•
•
Investigating two or more bands of a spectrum by separate detectors
3
/
40
•
•
Measuring the intensity of spectral lines by determining density of a photograph of the spectrum; Spectrography (G 01 J 3/42, G 01 J 3/44 take precedence) [4]
Correlation spectrometry, e.g. of the intensity (G 01 J 3/453 takes precedence) [4]
3
/
46
•
Measurement of colour; Colour measuring devices, e.g. colorimeters (measuring colour temperature G 01 J 5/60) [4]
3
/
50
•
•
using electric radiation detectors [4]
3
/
51
•
•
•
using colour filters [4]
3
/
52
•
•
using colour charts
4
/
00
Measuring polarisation of light (investigating or analysing materials by measuring rotation of plane of polarised light G 01 N 21/21) [2]
4
/
02
•
Polarimeters of separated-field type; Polarimeters of half-shadow type [2]
4
/
04
•
Polarimeters using electric detection means (G 01 J 4/02 takes precedence) [2]
5
/
00
Radiation pyrometry (photometry in general
G 01 J 1/00; spectrometry in general G 01 J 3/00)
5
/
02
•
Details
5
/
04
•
•
Casings
5
/
06
•
•
Arrangements for eliminating effects of disturbing radiation
5
/
08
•
•
Optical features
5
/
10
•
using electric radiation detectors
5
/
12
•
•
using thermoelectric elements, e.g. thermocouples (thermoelectric elements per seH 01 L 35/00, H 01 L 37/00)
5
/
14
•
•
•
Electrical features
5
/
16
•
•
•
•
Arrangements with respect to the cold junction; Compensating influence of ambient temperature or other variables
5
/
18
•
•
•
•
Special adaptation for indicating or recording (indicating or recording measured values in general G 01 D)
5
/
20
•
•
using resistors, thermistors, or semiconductors sensitive to radiation
5
/
22
•
•
•
Electrical features
5
/
24
•
•
•
•
Use of a specially-adapted circuit, e.g. bridge circuit
5
/
26
•
•
•
•
Special adaptation for indicating or recording
5
/
28
•
•
using photo-emissive, photo-conductive, or photo-voltaic cells
5
/
30
•
•
•
Electrical features
5
/
32
•
•
•
•
Special adaptation for indicating or recording
5
/
34
•
•
using capacitors
5
/
36
•
•
using ionisation of gases
5
/
38
•
using extension or expansion of solids or fluids
5
/
40
•
•
using bimetallic elements
5
/
42
•
•
using Golay cells
5
/
44
•
•
using change of resonant frequency, e.g. of piezo-electric crystal
5
/
46
•
using radiation pressure or radiometer effect
5
/
48
•
using wholly visual means
5
/
50
•
using techniques specified in the subgroups below
5
/
52
•
•
using comparison with reference sources, e.g. disappearing-filament pyrometer
5
/
54
•
•
•
Optical features
5
/
56
•
•
•
Electrical features
5
/
58
•
•
using absorption; using polarisation; using extinction effect
5
/
60
•
•
using determination of colour temperature
5
/
62
•
•
using means for chopping the light
7
/
00
Measuring velocity of light
9
/
00
Measuring optical phase difference (devices or arrangements for controlling the phase of light beams G 02 F 1/01); Determining degree of coherence; Measuring optical wavelength (spectrometry G 02 F 3/00) [3]
9
/
02
•
by interferometric methods (using interferometers for measuring optically the linear dimensions of objects G 01 B 9/02) [3]
9
/
04
•
by beating two waves of the same source but of different frequency and measuring the phase shift of the lower frequency obtained [3]
11
/
00
Measuring the characteristics of individual optical pulses or of optical pulse trains [5]
