Radiometric measuring of thin fluid films
AssigneeMicroFluid AB
InventorCronvall Leif
Life of this patent
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Abstract
The present invention relates to radiometric measurement of a thin fluid film using absorption of IR radiation. At least one IR radiator is directed to send signals to an IR detector via a bed on which the fluid film is placed. The IR detector is set to receive IR radiation in a band around a characteristic absorption band of the fluid of the fluid film. The invention is developed for printing presses, where the thickness of fountain solution on the printing plate and the proportion of printing ink in an emulsion of printing ink and fountain solution may be controlled.
Claims15
A method for radiometric measurement of thin fluid films (4) where absorption of IR radiation is used, and at least one IR radiator (1) is directed to send signals to a connected IR detector (2) by means of the fluid film (4) to be measured characterized in that the method is used for a printing press and that the fluid film (4) consists of fountain solution or an emulsion of fountain solution and printing ink, received on a printing plate (3) or other printing equipment.
The method of any of the previous claims, characterized in that the signals from the at least one IR detector (2) are given to a control unit.
The method of any of the previous claims, characterized in that the signal is pulsated or continuous;
- that the measurements are presented in real time or after processing of the measurements;
- that the IR radiator (1) sends IR radiation in a broad or narrow range;
- that one or more filters are placed at the IR detector (2) or IR radiator (1) to limit the received IR radiation to a band and that the absorption band is the main absorption band of the fluid to be measured.
The method of any of the previous claims, characterized in that several points of measurement are monitored and that the power of IR radiation in at least one of the points of measurement is set in relation to a specific printing ink.
The method of any of the previous claims, characterized in that the characteristic absorption band of the fluid of the fluid film (4) is first determined and that the wavelength of the IR radiation to be received by the IR detector (2) is set to a band in a range where the fluid or separate ingredients of it has significant absorption.
A device for measurement according to the method of any of the previous claims, characterized in that it comprises at least one unit (5, 6) comprising an IR radiator (1) and an IR detector (2), a signal processing system and other support systems and that it is provided at a printing press, where the at least one unit (5, 6) measures on a non-printing area (12) and a printing area (13) of the printing plate and that a control unit (7) receive information from further sensors (8) or meters (9).
Dependencies are inferred from the claim text.