• 한국정밀공학회지
• /
• 제11권6호
• /
• pp.168-178
• /
• 1994

This paper presents an optical surface roughness sensor developed for intermediate- process measurement on the machine. The light scattering method is adopted for the sensor, which is designed conpact and flexible enough to apply to 'on the machine' measurement of surface roughness. The developed sensor has special features such that it makes use, as the measurement parameter, of the ratio between fluxes of the incident light, and the specularly and partly diffusely reflected light, and that it can adjust the incident light angle. The experimental investigation reveals not only the sensor has good performance as a surface roughness sensor but the sensor is very robust so as to be useful in in-process measurement.

• 한국정밀공학회지
• /
• 제16권2호통권95호
• /
• pp.145-152
• /
• 1999

This paper presents the principle and experimental results of a non-contact surface roughness measurement by means of screen projected pattern of lase beam reflected from a polished surface. In the reflected laser beam pattern especially from a fine surface like ground or polished one, light intensity varies from the center fo the image to its boundary as the Gaussian distribution. The standard deviation of a light intensity distribution is assumed to be a good non-contact estimator for measuring the surface roughnes, because the light reflectivity is known to be well related with the surface roughness. This method doesn't need to discriminate between the specularly reflected light and the diffusely reflected one, whereas the scattered laser intensity method must do. Nor it needs to adjust the change of light intensity caused by environmental lights or specimen materials. Reflected laser beam pattern narrowly spreads out in the vertical direction to tiny scratches on the polished surface due to abrasives. The deeper the scratch the more the dispersion, which means the rougher surface. The standard deviation of the pattern is nearly in proportion to the surface roughness. Measurement errors by this method are shown to be below 10 percent compared with those obtained by a common contact method. The inclination of measuring unit from the normal axis causes the measurement errors up to 10 percent for an angle of 4 degree. Therefore the proposed method can be used as an on-the-machine quick roughness estimator within 10 percent measurement error.

• 한국정밀공학회지
• /
• 제12권4호
• /
• pp.46-54
• /
• 1995

This paper presents a simple method for measurenemt of roughness of ground surfaces. The present method utilizes fluxes of scattered lights condensed through lenses aligned along the specular direction. A theoretical analysis is preformed for the purpose of investigating the possibility of the method as well as determining the experimental condition. Experiments are also performed to show the effectiveness and robustness of the proposed method. The theoretical and experimental results show that the proposed method is simple enouth to implement and has a potential to identify a wide range of roughness of ground surfaces.

• 대한의용생체공학회:의공학회지
• /
• 제13권2호
• /
• pp.141-146
• /
• 1992

The propagation, reflection and scattering characteristics of the near Infra-red lights were experimented in order to check the feasibility of non-restrained biotelemetry using indirect transmitted light. The results of the experiments show that 3 kinds of walls examined are not specular reflectors but almost perfect diffuse surfaces with slight directivity and that light in a local point is spread out and fills the room uniformly by repeating the reflection and scattering at walls, ceiling, floor. These results also explain the fact that the diffusely reflected light can be utilized as the carrier of biotelemetry even after several scattering and reflections.

• 천문학회지
• /
• 제33권3호
• /
• pp.165-172
• /
• 2000

A baffle system for an airglow photometer, which will be on board the Korea Sounding Rocket-III(KSR-III), has been designed to suppress strong solar scattered lights from the atmosphere below the earth limb. Basic principles for designing a baffle system, such as determination of baffle dimensions, arrangement of vanes inside a baffle tube, and coating of surfaces, have been reviewed from the literature. By considering the constraints of the payload size of the KSR-III and the incident angle of solar light scattered from the earth limb, we first determined dimensions of a two-stage baffle tube for the airglow photometer. We then calculated positions and heights of vanes to prohibit diffusely reflected lights inside the baffle tube from entering into the photometer. In order to evaluate performance of the designed baffle system, we have developed a ray tracing program using a Monte Carlo method. The program computed attenuation factors of the baffle system on the order of $10^{-6}$ for angles larger than $10^{\circ}$, which satisfies the requirements of the KSR-III airglow experiment. We have also measured the attenuation factors for an engineering model of the baffle system with a simple collimating beam apparatus, and confirmed the attenuation factors up to about $10^{-4}$. Limitation of the apparatus does not allow to make more accurate measurements of the attenuation factors.