A web manufacturing supervision system for monitoring properties of a web being transported in a moving direction during a web manufacturing process, includes: a) a radiation source for illuminating a first spot on the web; b) a tunable first detector for capturing signal radiation emanating from the first spot within a signal wavelength band; the signal wavelength band being adjustable to one of at least a first wavelength band and a second wavelength band; c) a second detector for capturing reference radiation emanating from the first spot within a reference wavelength band; d) control means for alternatingly tuning the signal wavelength band to the first wavelength band and the second wavelength band and measuring the signal at both wavelength bands simultaneously.

A measurement apparatus of a moving paper web, includes an optical radiation source that outputs optical radiation toward a scattering element of the measurement apparatus. The scattering element scatters the optical radiation, and a transmitting surface of the scattering element directs the optical radiation in a scattered manner toward the moving paper web. A distance between said transmitting surface of the scattering element and a surface of the paper web is known, and the transmitting surface and a detector of the apparatus are on opposite sides of the paper web. The detector receives at least a part of the optical radiation, which is side-scattered from the moving paper web. The detector determines a moisture value and a dry weight of the paper web on the basis of spectral information on the received optical radiation and the known distance.

A measurement apparatus of a moving paper web, includes an optical radiation source that outputs optical radiation toward a scattering element of the measurement apparatus. The scattering element scatters the optical radiation, and a transmitting surface of the scattering element directs the optical radiation in a scattered manner toward the moving paper web. A distance between said transmitting surface of the scattering element and a surface of the paper web is known, and the transmitting surface and a detector of the apparatus are on opposite sides of the paper web. The detector receives at least a part of the optical radiation, which is side-scattered from the moving paper web. The detector determines a moisture value and a dry weight of the paper web on the basis of spectral information on the received optical radiation and the known distance.

A measurement device to measure a physical quantity of a measurement target having a sheet-like shape is provided, including: a first integrating sphere which is separated by a gap from a first surface of the measurement target, has a first opening facing the first surface, and is not provided with a light detector to detect an intensity of light; a second integrating sphere which is separated by a gap from a second surface of the measurement target, where the second surface is positioned opposite to the first surface, and has a second opening facing the first opening with the measurement target sandwiched therebetween; a light source to emit light into the first integrating sphere; a light detecting unit to detect an intensity of light inside the second integrating sphere; and a calculating unit to calculate the physical quantity of the measurement target based on the intensity of the detected light.

A measurement device to measure a physical quantity of a measurement target having a sheet-like shape is provided, including: a first integrating sphere which is separated by a gap from a first surface of the measurement target, has a first opening facing the first surface, and is not provided with a light detector to detect an intensity of light; a second integrating sphere which is separated by a gap from a second surface of the measurement target, where the second surface is positioned opposite to the first surface, and has a second opening facing the first opening with the measurement target sandwiched therebetween; a light source to emit light into the first integrating sphere; a light detecting unit to detect an intensity of light inside the second integrating sphere; and a calculating unit to calculate the physical quantity of the measurement target based on the intensity of the detected light.

A measurement device to measure a physical quantity of a measurement target having a sheet-like shape is provided, including: a first integrating sphere which is separated by a gap from a first surface of the measurement target, has a first opening facing the first surface, and is not provided with a light detector to detect an intensity of light; a second integrating sphere which is separated by a gap from a second surface of the measurement target, where the second surface is positioned opposite to the first surface, and has a second opening facing the first opening with the measurement target sandwiched therebetween; a light source to emit light into the first integrating sphere; a light detecting unit to detect an intensity of light inside the second integrating sphere; and a calculating unit to calculate the physical quantity of the measurement target based on the intensity of the detected light.

A measurement device to measure a physical quantity of a measurement target having a sheet-like shape is provided, including: a first integrating sphere which is separated by a gap from a first surface of the measurement target, has a first opening facing the first surface, and is not provided with a light detector to detect an intensity of light; a second integrating sphere which is separated by a gap from a second surface of the measurement target, where the second surface is positioned opposite to the first surface, and has a second opening facing the first opening with the measurement target sandwiched therebetween; a light source to emit light into the first integrating sphere; a light detecting unit to detect an intensity of light inside the second integrating sphere; and a calculating unit to calculate the physical quantity of the measurement target based on the intensity of the detected light.

A moisture detecting apparatus includes: a light emitting unit including a first light source configured to emit light having a first wavelength as a peak wavelength, and a second light source configured to emit light having a second wavelength as a peak wavelength; a detecting unit configured to detect a first detection value indicating an extent to which the light emitted from the first light source is transmitted through a recording material, and a second detection value indicating an extent to which the light emitted by the second light source is transmitted through the recording material, based on a light receiving result of a light receiving unit; and a determination unit configured to determine a value related to a moisture content of the recording material based on the first detection value and the second detection value.

A moisture detecting apparatus includes: a light emitting unit including a first light source configured to emit light having a first wavelength as a peak wavelength, and a second light source configured to emit light having a second wavelength as a peak wavelength; a detecting unit configured to detect a first detection value indicating an extent to which the light emitted from the first light source is transmitted through a recording material, and a second detection value indicating an extent to which the light emitted by the second light source is transmitted through the recording material, based on a light receiving result of a light receiving unit; and a determination unit configured to determine a value related to a moisture content of the recording material based on the first detection value and the second detection value.

A moisture detecting apparatus includes: a light emitting unit including a first light source configured to emit light having a first wavelength as a peak wavelength, and a second light source configured to emit light having a second wavelength as a peak wavelength; a detecting unit configured to detect a first detection value indicating an extent to which the light emitted from the first light source is transmitted through a recording material, and a second detection value indicating an extent to which the light emitted by the second light source is transmitted through the recording material, based on a light receiving result of a light receiving unit; and a determination unit configured to determine a value related to a moisture content of the recording material based on the first detection value and the second detection value.