Schematic of a lens and a flat plate used to form Newton’s rings
Note: VGA monitor not included
Features
Microscopic CMOS color camera with displacement cursor
Newton's ring pattern displayed on VGA color monitor
Direct measurement using keypad controlled cursor on LCD color monitor
Camera and Sodium lamp available for other applications
Introduction
The phenomenon of Newton's rings, named after Isaac Newton, is an interference pattern caused by the reflection of light between two surfaces - a spherical surface and an adjacent flat surface. When viewed with monochromatic light, it appears as a series of concentric, alternating light and dark rings centered at the point of contact between the two surfaces.
This apparatus uses an area VGA output color camera with a microscopic lens to acquire the Newton's ring pattern. The acquired pattern can be measured directly using a set of keypad controlled cursors on a LCD monitor. Using this apparatus, students can observe the phenomenon of equal-thickness interference. By measuring interference fringe separation, the radius of curvature of the spherical surface can be calculated.
The instruction manual contains comprehensive materials including experimental configurations, principles and step-by-step instructions. Please click to view some sample pages of the instruction manual.
Specifications
| Item | Specifications |
| Light Source | low pressure sodium lamp, 20 W |
| Newton's Ring Device | radius of curvature: ~868.5 mm; diameter: 32 mm; transmissive |
| Electronic Scale | resolution: 0.01 mm; viewing field: ~ 10 mm |
CMOS Color Camera | sensor size: 1/4" |
| resolution: 1280 × 1024 | |
| pixel size: 2.8 μm x 2.8 μm | |
| bit: 8 | |
| output format: VGA | |
| frame rate: 15 Hz | |
| optical mount: C/CS | |
| function setting: via keypad and menu | |
| menu functions: brightness, contrast, saturation, sharpness, tone, cursor, length | |
| Camera Lens | focal length: 25 mm |
Part List
| Description | Qty |
| Sodium lamp with housing and power supply | 1 set |
| CMOS color camera with AC adapter | 1 set |
| Camera lens with extension ring | 1 |
| Newton's ring assembly | 1 |
| Beam splitter with mount and post | 1 set |
| Camera stand with focusing knob | 1 set |
| Keypad | 1 |
| VGA flat panel monitor (optional) | 1 |
Schematic of a lens and a flat plate used to form Newton’s rings
