Surveying specially adapted to open water, e.g. sea, lake, river, canal (liquid level metering
G 01 F; measuring liquid velocity G 01 P; determining existence or flow of underground water G 01 V)
Plumbing or registering staffs or markers over ground marks
15
/
10
•
Plumb lines
15
/
12
•
Instruments for setting out fixed angles, e.g. right angles
15
/
14
•
Artificial horizons (tilt compensation in general G 12 B 5/00)
17
/
00
Compasses; Devices for ascertaining true or magnetic north for navigation or surveying purposes (using gyroscopic effect G 01 C 19/00; for geophysical or prospecting purposes G 01 V 3/00)
17
/
02
•
Magnetic compasses
17
/
04
•
•
with north-seeking magnetic elements, e.g. needles
17
/
06
•
•
•
Suspending magnetic elements
17
/
08
•
•
•
•
by flotation
17
/
10
•
•
•
Comparing observed direction with north indication
17
/
12
•
•
•
•
by sighting means, e.g. for surveyors' compasses
17
/
14
•
•
•
•
by reference marks, e.g. for ships' compasses
17
/
16
•
•
•
•
by clinometers, e.g. for determining dip or strike of geological strata
17
/
18
•
•
•
Supporting or suspending compasses, e.g. by gimbal, by flotation
17
/
20
•
•
•
Observing the compass card or needle
17
/
22
•
•
•
•
by projection
17
/
24
•
•
•
•
Illumination
17
/
26
•
•
•
•
using electric pick-offs for transmission to final indicator, e.g. photocell
17
/
28
•
•
Electromagnetic compasses (with north-seeking magnetic elements and having electric pick-offs G 01 C 17/26)
17
/
30
•
•
•
Earth-inductor compasses
17
/
32
•
•
•
Electron compasses
17
/
34
•
Sun- or astro-compasses
17
/
36
•
Repeaters for remote indication of readings of a master compass
17
/
38
•
Testing, calibrating, or compensating of compasses
19
/
00
Gyroscopes; Turn-sensitive devices using gyroscopic effect, e.g. using gas, using electron beam
19
/
02
•
Rotary gyroscopes
19
/
04
•
•
Details
19
/
06
•
•
•
Rotors
19
/
08
•
•
•
•
electrically driven (G 01 C 19/14
takes precedence; dynamo-electric machines H 02 K)
Suspensions; Bearings (bearings in general F 16 C; balancing rotors G 01 M)
19
/
18
•
•
•
•
providing movement of rotor with respect to its rotational axes (G 01 C 19/20, G 01 C 19/24 take precedence)
19
/
20
•
•
•
•
in fluid
19
/
22
•
•
•
•
torsional
19
/
24
•
•
•
•
using magnetic or electrostatic fields
19
/
26
•
•
•
Caging, i.e. immobilising moving parts, e.g. for transport (applicable to instruments in general G 01 D 11/20)
19
/
28
•
•
•
Pick-offs, i.e. devices for taking off an indication of the displacement of the rotor axis
19
/
30
•
•
•
Erection devices, i.e. devices for restoring rotor axis to a desired position (for instrument indicating the vertical G 01 C 19/46)
19
/
32
•
•
•
Indicating or recording means specially adapted for rotary gyroscopes (in general G 01 D)
19
/
34
•
•
for indicating a direction in the horizontal plane, e.g. directional gyroscopes
19
/
36
•
•
•
with north-seeking action by magnetic means, e.g. gyromagnetic compasses
19
/
38
•
•
•
with north-seeking action by other than magnetic means, e.g. gyrocompasses using earth's rotation
19
/
40
•
•
for control by signals from a master compass, i.e. repeater compasses
19
/
42
•
•
for indicating rate of turn; for integrating rate of turn
19
/
44
•
•
for indicating the vertical
19
/
46
•
•
•
Erection devices for restoring rotor axis to a desired position
19
/
48
•
•
•
•
operating by electrical means (G 01 C 19/54
takes precedence)
19
/
50
•
•
•
•
operating by mechanical means (G 01 C 19/54 takes precedence)
19
/
52
•
•
•
•
operating by fluid means (G 01 C 19/54 takes precedence)
19
/
54
•
•
•
•
with correction for acceleration forces due to movement of instrument
19
/
56
•
Turn-sensitive devices with vibrating masses, e.g. tuning fork
19
/
58
•
Turn sensitive devices without moving masses [3]
19
/
60
•
•
Electronic or nuclear magnetic resonance gyrometers (magnetic resonance arrangements in general G 01 R 33/20) [3,4]
19
/
62
•
•
•
with optical pumping [3]
19
/
64
•
•
Gyrometers using the Sagnac effect, i.e. rotation-induced shifts between counter-rotating electromagnetic beams [3]
19
/
66
•
•
•
Ring laser gyrometers (ring lasers in general H 01 S 3/083) [5]
19
/
68
•
•
•
•
Lock-in prevention [5]
19
/
70
•
•
•
•
•
by mechanical means [5]
19
/
72
•
•
•
with counter-rotating light beams in a passive ring, e.g. fibre laser gyrometers [5]
21
/
00
Navigation; Navigational instruments not provided for in preceding groups (measuring distance traversed on the ground by a vehicle G 01 C 22/00; measuring linear or angular speed or acceleration G 01 P)
21
/
02
•
by astronomical means (G 01 C 21/24 takes precedence; measuring time by using position of the sun, moon, or stars G 04 B 49/00)
21
/
04
•
by terrestrial means (G 01 C 21/24 takes precedence; marking of navigation route for ships B 63 B 51/00)
21
/
06
•
•
involving measuring of drift angle; involving correction for drift
21
/
08
•
•
involving use of the magnetic field of the earth
21
/
10
•
by using measurement of speed or acceleration (G 01 C 21/24
takes precedence)
21
/
12
•
•
executed aboard the object being navigated; Dead reckoning
21
/
14
•
•
•
by recording the course traversed by the object (G 01 C 21/16 takes precedence)
21
/
16
•
•
•
by integrating acceleration or speed, i.e. inertial navigation
21
/
18
•
•
•
•
Stabilised platforms, e.g. by gyroscope
21
/
20
•
Instruments for performing navigational calculations (G 01 C 21/24 takes precedence; computing in general G 06)
Measuring distance traversed on the ground by vehicles, persons, animals, or other moving solid bodies, e.g. using odometers, using pedometers (counting mechanisms per seG 06 M)
22
/
02
•
by conversion into electric waveforms and subsequent integration, e.g. using tachometer generator
23
/
00
Combined instruments indicating more than one navigational value, e.g. for aircraft; Combined measuring devices for measuring two or more variables of movement, e.g. distance, speed, acceleration
25
/
00
Manufacturing, calibrating, cleaning, or repairing instruments or devices referred to in the preceding groups (testing, calibrating, or compensating compasses G 01 C 17/38)
