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.

A signal detection device according to one aspect of the present invention includes a receiver configured to receive a signal including at least a first signal component modulated by a first frequency and a second signal component modulated by a second frequency, and a detector configured to generate, using a base signal, a first reference signal to be used for detecting the first signal component and a second reference signal to be used for detecting the second signal component, perform lock-in detection on the signal received by the receiver using the first reference signal to obtain a first detection signal, perform lock-in detection on the signal received by the receiver using the second reference signal to obtain two second detection signals having different phases from each other, and change at least one of a frequency and a phase of each of the first and second reference signals to set one of the two second detection signals to zero.

A signal detection device according to one aspect of the present invention includes a receiver configured to receive a signal including at least a first signal component modulated by a first frequency and a second signal component modulated by a second frequency, and a detector configured to generate, using a base signal, a first reference signal to be used for detecting the first signal component and a second reference signal to be used for detecting the second signal component, perform lock-in detection on the signal received by the receiver using the first reference signal to obtain a first detection signal, perform lock-in detection on the signal received by the receiver using the second reference signal to obtain two second detection signals having different phases from each other, and change at least one of a frequency and a phase of each of the first and second reference signals to set one of the two second detection signals to zero.

An example apparatus for determining dryness of an agent on print media includes an infrared prism, a source of infrared radiation to direct infrared radiation into the infrared prism, and a detector. The infrared prism includes a surface, the surface having an outer side to contact a portion of the agent on the print media, the infrared prism having a refractive index that is higher than a refractive index of the agent. The source of infrared radiation is to direct infrared radiation into the infrared prism and onto an inner side of the surface. The detector is to generate a signal based on infrared radiation reflected by the inner side of the surface to indicate the dryness of the portion of the agent.

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 and equal to or less than 25; 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.

A system for determining at least one property of a sheet dielectric sample using terahertz radiation includes at least one terahertz transmitter configured to output a pulse of terahertz radiation, a terahertz receiver configured to receive at least a portion of the pulse of terahertz radiation, wherein the terahertz receiver is configured to output a measured waveform based on the terahertz radiation received by the terahertz receiver, and a control unit in communication with the terahertz receiver. Wherein the control unit is configured to choose at least one region of interest of the measured waveform, compare the at least one region of interest of the measured waveform to a model waveform, vary at least one parameter of a model waveform to minimize the difference between the model waveform and the measured waveform.

A system for determining at least one property of a sheet dielectric sample using terahertz radiation includes at least one terahertz transmitter configured to output a pulse of terahertz radiation, a terahertz receiver configured to receive at least a portion of the pulse of terahertz radiation, wherein the terahertz receiver is configured to output a measured waveform based on the terahertz radiation received by the terahertz receiver, and a control unit in communication with the terahertz receiver. Wherein the control unit is configured to choose at least one region of interest of the measured waveform, compare the at least one region of interest of the measured waveform to a model waveform, vary at least one parameter of a model waveform to minimize the difference between the model waveform and the measured waveform.

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 method of calculating a first parameter of a first sample of a material is provided. The method includes determining a first and second wavelengths at which the material exhibits substantially no absorption; measuring a transmission of the first sample at the first wavelength; measuring a transmission of the first sample at the second wavelength; and calculating the first parameter of the first sample using a first multivariate regression model including first regression coefficients. The first parameter is a parameter which affects a total amount of radiation scattered by the first sample at the first and second wavelengths.

A method of calculating a first parameter of a first sample of a material is provided. The method includes determining a first and second wavelengths at which the material exhibits substantially no absorption; measuring a transmission of the first sample at the first wavelength; measuring a transmission of the first sample at the second wavelength; and calculating the first parameter of the first sample using a first multivariate regression model including first regression coefficients. The first parameter is a parameter which affects a total amount of radiation scattered by the first sample at the first and second wavelengths.