Document ID: chunk:federal_register_of_legislation:F2024L01024:front:0:p208
Version: federal_register_of_legislation:F2024L01024
Segment Type: other
Provision Reference: 
Character Range: 597472–600449

(rms) per square root Hz at frequencies of 1 Hz or more but not exceeding 10 Hz; or
c. 1 x 10‑4 nT (rms) per square root Hz at frequencies exceeding 10 Hz;
5. Fibre optic "magnetometers" having a 'sensitivity' lower (better) than 1 nT (rms) per square root Hz;
6. A. 006. b. Underwater electric field sensors having a 'sensitivity' lower (better) than 8 nanovolt per metre per square root Hz when measured at 1 Hz;
6. A. 006. c. "Magnetic gradiometers" as follows:
1. "Magnetic gradiometers" using multiple "magnetometers" specified by 6A006.a.;
2. Fibre optic "intrinsic magnetic gradiometers" having a magnetic gradient field 'sensitivity' lower (better) than 0.3 nT/m rms per square root Hz;
3. "Intrinsic magnetic gradiometers", using "technology" other than fibre‑optic "technology", having a magnetic gradient field 'sensitivity' lower (better) than 0.015 nT/m rms per square root Hz;
6. A. 006. d. "Compensation systems" for magnetic or underwater electric field sensors resulting in a performance equal to or better than the specified parameters of 6A006.a., 6A006.b. or 6A006.c.
6. A. 006. e. Underwater electromagnetic receivers incorporating magnetic field sensors specified by 6A006.a. or underwater electric field sensors specified by 6A006.b.
Technical Note:
For the purposes of 6A006., 'sensitivity' (noise level) is the root mean square of the device‑limited noise floor which is the lowest signal that can be measured.
 GRAVIMETERS
6. A. 007. Gravity meters (gravimeters) and gravity gradiometers, as follows:
N.B.: SEE ALSO 6A107.
a. Gravity meters designed or modified for ground use and having a static "accuracy" of less (better) than 10 µGal;
Note: 6A007.a. does not apply to ground gravity meters of the quartz element (Worden) type.
6. A. 007. b. Gravity meters designed for mobile platforms and having all of the following:
1. A static "accuracy" of less (better) than 0.7 mGal; and
2. An in‑service (operational) "accuracy" of less (better) than 0.7 mGal having a 'time to steady‑state registration' of less than 2 minutes under any combination of attendant corrective compensations and motional influences;
Technical Note:
           For the purposes of 6A007.b.2., 'time-to-steady-state registration' (also referred to as the gravimeter's response time) is the time over which the disturbing effects of platform induced accelerations (high frequency noise) are reduced.
6. A. 007. c. Gravity gradiometers.
 RADAR
6. A. 008. Radar systems, equipment and assemblies, having any of the following, and specially designed components therefor:
N.B.: SEE ALSO 6A108.
Note: 6A008 does not apply to:
a. Secondary surveillance radar (SSR);
b. Civil Automotive Radar;
c. Displays or monitors used for air traffic control (ATC);
d. Meteorological (weather) radar;
e. Precision approach radar (PAR) equipment conforming to ICAO standards and employing electronically steerable linear (1‑dimensional) arrays or mechanically positioned passive antennae.
6. A. 008.