A processing device includes a first light source and a second light source configured to emit light having a peak wavelength from 900 nm to 2,100 nm, a first light receiving portion, a second light receiving portion, and a processing portion configured to subject a medium to processing of increasing or reducing an amount of moisture contained in the medium. the first light source and the first light receiving portion are positioned upstream of the processing portion in a transport direction of the medium, the first light source irradiates, with light, the medium, the first light receiving portion receives light reflected by the medium, the second light source and the second light receiving portion are positioned downstream of the processing portion in the transport direction, the second light source irradiates, with light, the medium, and the second light receiving portion receives light reflected by the medium.

A detecting apparatus includes first and second light emitting elements configured to emit light on a recording material, and a light receiving unit configured to receive the light transmitted through the recording material. The apparatus also includes a rotation member configured to rotate and press the recording material, on which the first light and the second light is emitted, against a conveyance guide for guiding the recording material. As viewed in a rotational axis direction of the rotation member, a first light path connecting the first light emitting element with the light receiving unit and a second light path connecting the second light emitting element with the light receiving unit overlap with the cylindrical member.

A detecting apparatus includes first and second light emitting elements configured to emit light on a recording material, and a light receiving unit configured to receive the light transmitted through the recording material. The apparatus also includes a rotation member configured to rotate and press the recording material, on which the first light and the second light is emitted, against a conveyance guide for guiding the recording material. As viewed in a rotational axis direction of the rotation member, a first light path connecting the first light emitting element with the light receiving unit and a second light path connecting the second light emitting element with the light receiving unit overlap with the cylindrical member.

A measuring device includes: an irradiator that irradiates electromagnetic waves to an inspection object; a light collector having a reflecting surface that guides, to a light-collecting surface, electromagnetic waves whose incident angle with respect to an incident end facing the inspection object is within a predetermined angle, among the electromagnetic waves that have been transmitted through the inspection object; and a detector that detects the electromagnetic waves guided to the light-collecting surface. The measuring device measures a characteristic of the inspection object based on the detected electromagnetic waves.

A measuring device includes: an irradiator that irradiates electromagnetic waves to an inspection object; a light collector having a reflecting surface that guides, to a light-collecting surface, electromagnetic waves whose incident angle with respect to an incident end facing the inspection object is within a predetermined angle, among the electromagnetic waves that have been transmitted through the inspection object; and a detector that detects the electromagnetic waves guided to the light-collecting surface. The measuring device measures a characteristic of the inspection object based on the detected electromagnetic waves.

Provided is a resin determination method including: placing an object on a placement surface with a diffusion reflectance of equal to or greater than 80% in an effective wavelength region of infrared light and with arithmetic mean roughness of equal to or greater than 0.25 m and equal to or less than 25 m; irradiating the object with infrared light; receiving reflected light from the object that has been irradiated with the infrared light; and determining a resin type based on a reflection spectrum or an absorption spectrum obtained by the reflected light.

Provided is a resin determination method including: placing an object on a placement surface with a diffusion reflectance of equal to or greater than 80% in an effective wavelength region of infrared light and with arithmetic mean roughness of equal to or greater than 0.25 m and equal to or less than 25 m; irradiating the object with infrared light; receiving reflected light from the object that has been irradiated with the infrared light; and determining a resin type based on a reflection spectrum or an absorption spectrum obtained by the reflected light.

Optical multi-channel measurement unit for a process measurement includes first ends for receiving optical radiation from the optical radiation source, and second ends for outputting the optical radiation for illuminating the at least one object. Optical detectors receive optical radiation from at least one measurement channel via at least one optical filter and convert an intensity of the optical radiation to an electrical signal. A movement mechanism causes, for filtering the wavelengths of the optical radiation propagating between detectors and the optical measurement channels through the optical filters, at least one of the following: movement inside at least one optical filter and movement between the filters and the detectors.

Optical multi-channel measurement unit for a process measurement includes first ends for receiving optical radiation from the optical radiation source, and second ends for outputting the optical radiation for illuminating the at least one object. Optical detectors receive optical radiation from at least one measurement channel via at least one optical filter and convert an intensity of the optical radiation to an electrical signal. A movement mechanism causes, for filtering the wavelengths of the optical radiation propagating between detectors and the optical measurement channels through the optical filters, at least one of the following: movement inside at least one optical filter and movement between the filters and the detectors.

A method for detecting a deflection or relative deflection between a source module and a detection module in a scanning apparatus and configured as a sensor pair for scanning transmission measurement of sheet material being transported in a machine direction through a sensing gap formed between the source module and the detection module is provided. The source module is arranged on a first side of the sensing gap and emits a sensing radiation or sensing energy radiation towards the sensing gap, and the detection module is arranged on a second side of the sensing gap opposite to the first side and detects the radiation from the source module and transmitted through the sensing gap. The method includes: attaching a removable blocking device to the detection module, so that a radiation-blocking area of the blocking device partially blocks, in an asymmetrical manner, a sub-area of the cross-sectional area of the radiation impinging onto a detection module aperture of the detection module; and performing a partially-blocked scanning process during which the source module and the detection module are jointly moved in a cross direction of the scanning apparatus, the source module emits the radiation and the detection module detects the radiation from the source module having transmitted through the sensing gap, whereby a selected portion of the radiation corresponding to the sub-area covered by the radiation-blocking area is blocked from being detected by the detection module aperture, whereby a partially-blocked sensor signal is obtained from the radiation detected by the detection module.