An oil concentration measurement system and method measure the concentration of oil over a wide concentration range and is applicable in a continuous measurement of oil concentration. A measurement-target liquid containing a known kind of oil component, absorbance spectrum is measured within a predetermined waveband where absorption of light is observed. If a predetermined criterion is met, a concentration value of the oil component is determined based on absorbance at a predetermined wavelength within the predetermined waveband and also on a first calibration curve showing relationship between the component concentration and absorbance at the predetermined wavelength. If the predetermined criterion is not met, a concentration value is determined based on the wavelength at which the absorbance has a predetermined absorbance value within the absorbance spectrum and also on a second calibration curve showing the relationship between the component concentration and wavelength at which the absorbance has the predetermined absorbance value.

An oil concentration measurement system and method measure the concentration of oil over a wide concentration range and is applicable in a continuous measurement of oil concentration. A measurement-target liquid containing a known kind of oil component, absorbance spectrum is measured within a predetermined waveband where absorption of light is observed. If a predetermined criterion is met, a concentration value of the oil component is determined based on absorbance at a predetermined wavelength within the predetermined waveband and also on a first calibration curve showing relationship between the component concentration and absorbance at the predetermined wavelength. If the predetermined criterion is not met, a concentration value is determined based on the wavelength at which the absorbance has a predetermined absorbance value within the absorbance spectrum and also on a second calibration curve showing the relationship between the component concentration and wavelength at which the absorbance has the predetermined absorbance value.

The invention relates to a device for monitoring water-miscible cooling lubricant comprising a chamber (1) and connections (2-5) for water, concentrate and water-miscible cooling lubricant. The connections are connected to the interior of the chamber by means of a mixer (6). The device comprises a refractometer (7), a source of electromagnetic radiation (8) and a digital camera (9) or a radiation detector. The digital camera or the radiation detector is connected to a data processing system (18) that controls the supply of water, the supply of water-miscible concentrate, the supply of water-miscible cooling lubricant of at least one machine tool and the medium-conveying apparatus in such a manner that a particular value or a particular range of the refraction caused by the water-miscible cooling lubricant is achieved and/or maintained and the determined amounts of water, concentrate and water-miscible cooling lubricant are recorded.

A coolant state estimation system that estimates a temporal change of a state of a coolant used in a processing machine includes a coolant state acquisition unit that acquires a measurement value regarding the state of the coolant as measurement information in which the measurement value is associated with measurement time of the measurement value, a processing information acquisition unit that acquires processing information on a processing condition of the processing machine, and an estimation unit that estimates a temporal change of the measurement value after the measurement time of the measurement information using a learned model based on the measurement information and the processing information. The learned model is a model that has learned the temporal change of the measurement value using teacher data created from the measurement information and the processing information.