Sextant

Basic Parameters
(1) Measurement Range: -5 to +130°
(2) Measurement accuracy: 40 arcseconds
(3) Discrimination rate: 8.75 arcseconds
(4) Telescope:
Magnification: 3.5X
Field of view: 5°
Objective lens diameter: 40 mm
Exit pupil diameter: 11 mm
(5) Illumination voltage: 3 volts
(6) Operating temperature range: -30 to 50°C
The nautical sextant is an optical instrument used to measure the angle between celestial bodies and the horizon—specifically, the altitude of celestial objects, the horizontal angle between two landmarks, and the vertical angle of a single landmark.
The sextant is a precision angular measurement instrument composed of three major components: the mount, the optical system, and the angular reading device. The optical system includes the telescope, movable prism, fixed prism, and filters; the angular reading device comprises the graduated arc, pointer rod, drum wheel, and vernier scale. All these components are mounted on the frame, with the optical system and angular reading device integrated into a single unit via the pointer rod. The sextant measures angles based on geometric principles such as: “the exterior angle of a triangle equals the sum of its two non-adjacent interior angles,” “corresponding angles in parallel lines are equal,” and “a central angle can be measured by the arc distance it subtends.”
Purpose
1. Determine the ship's position by measuring the altitude of celestial bodies.
2. Measure two horizontal angles between three known positions on the ground, then determine the ship's position on the chart using a three-rod quadrant.
3. Determine distance by measuring the vertical angle to a target of known height.
Instrument accessories
1. Sextant 1 unit
2. Monocular 1 unit
3. One spare light bulb
4. Calibration wrench 1 piece
5. Oil cruet 1
6. Screwdriver 1
7. Brush 1 piece
8. Cleaning cloth 1 piece
9. Instruction Manual 1 copy
10. Certificate of Conformity (1 copy)