An electro-optical device used to measure light intensity (a light meter).
instrument used to measure the intensity of a light source.
A device which measures the mass concentration of an aerosol by the amount of light the aerosol scatters.
Instrument that measures luminous intensity, luminous flux, light distribution or color.
A device that is used to measure the brightness of an object.
A device that measures the total amount of light received in all or part of the image.
Instrument used for measuring the concentration of DOP smoke particles up and downstream of a HEPA filter.
measuring instrument for measuring the luminous intensity of a source by comparing it (visually or photoelectrically) with a standard source
photographic equipment that measures the intensity of light
a more accurate way to measure the visible light and darkness quanta emitted by an object
an instrument used to precisely measure the brightness or intensity of light
An instrument for measuring a property of light, especially luminous intensity or flux. A photometer uses special colored filters to replicate the response of the human eye. Light intensity is measured in candle power, usually by comparison with a standard source.
The measurement of the intensity of light.
An optical instrument that measures the intensity of light from a source.
a device that measures an object's brightness, or apparent magnitude, by detecting its emitted photons.
An instrument for measuring the intensity of light or the relative intensity of a pair of lights. Also called an illuminometer. If the instrument is designed to measure the intensity of light as a function of wavelength, it is called a spectrophotometer. Photometers may be divided into two classes: photoelectric photometers in which a photoelectric cell is used to compare electrically the intensity of an unknown light with that of a standard light; and visual photometers in which the human eye performs the function of a photo cell. A photometer used to measure the intensity of a distant light is referred to as a telephotometer or transmissometer.
An instrument for measuring the intensity of light by comparing it with a standard.
A photometer is a meter that measures visible Illuminance light levels. The basic unit of luminance measurement is Candela per square meter (cd/m2). Both Lux and Candelas measure luminous intensity from a specific direction.
An instrument for measuring luminous intensity, luminous flux, illumination, or intensity.
Also called a light meter, this is an instrument used to measure luminous intensity, luminous flux, illumination, or intensity of light.
A light meter which when attached to the eyepiece of a telescope can measure the brightness of stars. The photometer will read out a number proportional to brightness. If we first look at stars whose brightness we know, we can use our photometer to measure the brightness of a unknown star. We use the SSP-3 photometers made by OPTEC Inc.
A light-sensitive detector placed at the focus of a telescope; it is used to make accurate measurements of small photon fluxes.
An electrical instrument for testing pool water conditions, which measures the colours electronically rather than visually, giving more accurate results.
Meter used to measure light intensity.
An instrument for measuring the luminance, luminous intensity, or illuminance of a light source. Analogous to radiometer, but with an output weighted by the wavelength response of the human eye (i.e., scaled by luminous efficiency). It is common in historical literature to see this term used for any radiometer that responds primarily to wavelengths that are visible to the human eye, with or without scaling for luminous efficiency. A photometer used to measure the intensity of a distant light is sometimes referred to as a telephotometer or transmissometer. See hydrophotometer, radiometer.
Any of a number of atmospheric phenomena which appear as luminous patterns in the sky. They do not directly cause adverse weather. They include halos, coronas. rainbows, and fogbows.
instrument for measuring light being reflected from a surface. It works by comparing the reflected light with a standard source produced within the photometer.
In the broadest sense, a photometer is any instrument used to measure illuminance or irradiance.