ГЭТ 94-2001 (НИО 253)
Standard name:
- ГЭТ 94-2001 State Primary Standard of Units of Linear Acceleration and Plane Angle for Angular Displacement of a Rigid Body
Type of measurement:
- Measurements of mechanical quantities
Structural division: name НИО\НИЛ:
- Research Department of Standards in the Fields of Measurement of Motion Parameters, Torque, Force and Gravimetry
Guardian Scientist:
- Yankovsky Alexander Anatolyevich
Year of creation:
- 1996
Year of re-confirmation:
- 2001
Operating principle:
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The EUP-3 reference setup utilizes the principle of equivalence of inertial and gravitational masses, allowing gravitational acceleration to be specified instead of inertial. The setup utilizes the method of tilting the instrument in the Earth's gravitational field, resulting in acceleration along the instrument's measurement axis equal to gsinf, where g is the acceleration due to gravity and f is the angle between the instrument's measurement axis and the horizontal plane. The setup utilizes an absolute method for determining the horizontal plane, using the surface of a free liquid as the plane.
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The DC-3 reference setup reproduces units of constant and variable linear acceleration using the rotary method. With the rotary table stationary, the setup is a single centrifuge, reproducing constant linear accelerations according to the expression
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where is the platform's angular velocity, and R is the distance between the axis of rotation and the center of mass of the device's sensitive element. With the simultaneous angular motion of both platforms, the setup functions as a double centrifuge and allows for the reproduction of harmonic linear accelerations according to the expression:
/formula-2.png)
where is the angular velocity of the turntable, R1 is the distance between the platform axes, and r is the distance between the turntable's axis of rotation and the center of mass of the sensitive element of the device under test. In this mode, constant and variable acceleration are simultaneously reproduced. If r = 0, the setup reproduces harmonic linear acceleration. The NC-3 reference setup reproduces the unit of variable linear acceleration using the variable projection of the acceleration of gravity onto the measuring axis of the device under test and the unit of plane angle during angular displacement of a rigid body using the goniometric method. When reproducing the unit of variable linear acceleration, a platform rotating at an angular velocity w is tilted from the vertical by an angle f, and, if the center of mass of the sensitive element of the device under test is located on the axis of rotation, the reproduced acceleration
/formula-3.png)
In plane angle unit reproduction mode, the goniometric method is implemented using two measuring transducers—a ring laser and an optical holographic transducer. The use of transducers that utilize fundamentally different physical effects enables the high resolution and scale uniformity inherent in ring lasers in angle measurement mode, and the high stability of the conversion coefficient inherent in holographic scales.
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Composition of the standard:
- Ustanovka povorotnaya EUP-3;
- Ustanovka rotatsionnaya s upravlyayemaya napravleniyem osi vrashcheniya NTS-3;
- Ustanovka rotatsionnaya DTS-3 (dvoynaya tsentrifuga).
- Rotary unit EUP-3;
- Rotary unit with controlled rotation axis direction NC-3;
- Rotary unit DC-3 (double centrifuge).
Main metrological characteristics
| Unit name | Range | Error | Uncertainty | ||||
|---|---|---|---|---|---|---|---|
| S0 | q0 | u0A | u0B | u0С | U0 | ||
| Harmonic linear acceleration | 1 × 10-4 — 250 m/s2 0.05-30 Hz | 1.5 × 10-5 – 2.5 × 10-3 m/s2 | 5 × 10-5 – 1 × 10-2 m/s2 | 1.5 × 10-5 – 2.5 × 10-3 m/s2 | 3 × 10-5 – 7 × 10-3 m/s2 | 3.2 × 10-5 – 7.5 × 10-3 m/s2 | 6.4 × 10-5 – 1.8 × 10-2 m/s2 |
| Constant linear acceleration | 5 × 10-5 — 500 m/s2 | 1.5 × 10-5 – 2.5 × 10-4 m/s2 | 2.5 × 10-5 – 1 × 10-3 m/s2 | 1.5 × 10-5 – 2.5 × 10-4 m/s2 | 1 × 10-5 – 6 × 10-4 m/s2 | 2.2 × 10-5 – 6.5 × 10-4 m/s2 | 4.4 × 10-5 – 1.3 × 10-3 m/s2 |
| Plane angle for angular displacement of a rigid body | 0.2 ² - 360 ° | 0.04 ² | 0.05 ² | 0.04 ² | 0.03 ² | 0.05 ² | 0.1 ² |
Verification diagram:
- Heads the state verification scheme for measuring instruments of linear acceleration and plane angle during angular displacement of a rigid body
Scope of application:
Space and defense technologies, shipbuilding, aircraft and rocket engineering, instrument making and precision engineering
Results of applying the standard:
- Transferring units to working standards for linear acceleration and plane angle;
- Ensuring certification of testing equipment designed to assess the conformity of defense products;
- Ensuring the determination of metrological characteristics of technical equipment with measuring capabilities, including those for defense purposes.
The total number of measuring instruments traceable to ГЭТ 94-2001:
Tens of thousands
Ensuring the uniformity of measurements, participation in the CIPM MRA program:
No comparisons were carried out
Unique technical installations as part of the standard:
None
PHOTO:
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/Установка поворотная ЭУП-3.png)
Rotary unit EUP-3
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/Установка ротационная ДЦ-3 (двойная центрифуга)..png)
Rotary unit DC-3 (double centrifuge).
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/Установка ротационная с управляемая направлением оси вращения НЦ-3.png)
Rotary installation with controlled direction of rotation axis NC-3