Density meter, colorimeter and spectrophotometer difference

Photometric instrument, density, color, spectral
Color measuring instruments according to structural principle can be divided into three types: density meter, colorimeter and spectrophotometer.
Density meter is the actual measurement of light absorbed by the ink or the film reflected the value of the value of the transmission. Is divided into reflection and transmission densimeter densimeter. Only the measurement of the absorption of various monochromatic light ratio of objects, saying only that “black” or “gray” level. Then you may want to ask: But obviously the density meter can measure the density of four-color ink ah? Indeed, the density meter can measure the density of four-color ink, but it is carried out using the filter. For example, it is used in the measurement of yellow ink blue filter, through the blue filter on the incident light filtering effect, leaving only blue light to yellow ink on the incident, but because of yellow ink absorbs blue light, its absorption of blue the extent of shade reflects the depth of yellow ink, so measuring the intensity of the reflected light can be aware of the extent of blue light is absorbed, also known yellow ink density. Therefore, the measurement of the same four-color ink to use is the ratio of the absorption of monochromatic light objects.
Colorimeter also features a set of special filter. However, the purpose of filter different from the same density meter, which is used to calibrate the instrument light source and detection components, the spectral characteristics of the size of the output signal is proportional to the color tristimulus values, and human visual harmony. Therefore, to imitate the eye colorimeter vision system can be drawn directly by measuring the color tristimulus values.
Spectrophotometer measurement of an object is within the scope of the entire visible reflectance spectra, which in the visible spectrum region were measured on a number of discrete points, usually at intervals of 10nm or 20nm measuring one point, 400 ~ 700mm measured in the range 16 ~ 31 points. Spectrophotometry using the digital integral method, any one wavelength of visible range spectral reflectance can be obtained, so it can offer much more than the colorimeter measured information, rather than just three stimulus values. Spectrophotometer can be used as a colorimeter, but also can measure the density value (digital signal to analog filter), more importantly, measurable spectrophotometer spectrophotometric curve, the differential diagnosis of the phenomenon of metamerism has a very important effect.
Measurement density meter colorimeter spectrophotometer
The use of a long history is not long not long
Price Low Medium High
Detection theory, the integrity of the complete incomplete incomplete
The accuracy of color measurement is not accurate
Difference between the consistency of instrument accuracy,
Associated with the human visual accuracy,
Has nothing to do with the human visual
Measurement of sampling points measured reflected light intensity measurement in the whole object of the tri-stimulus value of three points, within the scope of any visible wavelength reflectivity ,16-31 points
In the performance of the printing features in terms of the thickness of printing ink, printing ink and printing ink trapping characteristics of very convenient for different paper, ink, color original such as the measurement results are accurate and can be converted to density values and chroma values, can identify metamerism
Occasions for measurement of the three primary colors for ink and attached next to the signal of the occasion, and the film applied to print quality control and color management for color and color management

Tags: color, density, Photometric instrument, spectral