microphotometer
Definition
Noun: A microphotometer is a specialized scientific instrument, a type of densitometer, designed to measure extremely small variations in the optical density (darkness or opacity) of a sample across a very small, localized area.
Usage
The term is used in technical and scientific contexts, particularly in fields like astronomy, spectroscopy, and photographic analysis, where precise measurement of light transmission through minute areas is required. * Scientists used a microphotometer to analyze the density variations in the stellar spectrum recorded on the photographic plate. * The accuracy of the measurement depended on the calibration of the microphotometer.
Advanced Usage
- In historical astronomical research, a was essential for quantifying the intensity of spectral lines from photographic plates before the advent of digital CCD sensors.
- The device often operates by scanning a finely focused beam of light across the sample and measuring the transmitted or reflected light with a photoelectric cell.
Variants and Related Words
- Microphotometry (n): The technique or process of making measurements with a microphotometer.
- Densitometer (n): A more general instrument for measuring optical density; a microphotometer is a specialized type of densitometer.
- Photometer (n): A device that measures the intensity of light.
Synonyms
- Microdensitometer: A direct synonym often used interchangeably with microphotometer.
Related Terms
- Optical Density: The degree to which a material prevents the transmission of light.
- Spectrogram: A photographic record of a spectrum, often analyzed with a microphotometer.
Noun
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special kind of densitometer that measures density variations over a very small area
