A method, an apparatus, and a non-transitory computer-readable medium for measuring a height of a sample includes: receiving, by an optical sensor having pixels, an optical grating image of an illuminated optical grating reflected by a surface of the sample; determining, by a processor, a digital grating image by keeping values of first pixels of the optical grating image and resetting values of second pixels of the optical grating image; and determining the height based on a relationship between an integrated intensity of a portion of the digital grating image and the height.

The invention relates to a casting apparatus (1) for the production of a cast sheet (10) of homogenized tobacco material, said casting system comprising: a casting box (4) adapted to contain a slurry of the homogenized tobacco material; a movable support (7); a casting system adapted to deposit the slurry contained in the casting box (4) onto the movable support (7) so as to form the cast sheet (10); a sensor (30) to detect a thickness of the cast sheet (10); wherein the sensor (30) includes a slider (33) comprising a planar surface (36) adapted to be in contact to a top surface of the cast sheet and a height detector (38) adapted to measure the height of the planar surface (36) so as to derive the thickness of the cast sheet (10). The invention also relates to a method to measure the thickness of a homogenized tobacco sheet (10).

Time-of-flight measurements calculate the absolute caliper of a moving film independent of the film's index of refraction. A reflective fiber coupled terahertz gauge is mounted co-axially with a temperature stabilized Z-sensor positioned within a scanner head. The terahertz gauge monitors four reflections: (1) the reflection from a sensor window, (2, 3) the reflections from the top and bottom surfaces of the sheet product being measured, and (4) the reflection from a reflector that is placed behind the sheet. The Z-sensor monitors the distance between the reflector and the senor window. The terahertz reflection delays together with the Z distance measurements allow extraction of the caliper. Since the time delay due to the sheet is a function of thickness and index of refraction, the basis weight of the sheet can be determined by using a calibration of the sensor relating basis weight of the product to time delay.

The present invention provides a measurement method including while driving a measurement target region of a surface of a substrate in a first direction with respect to a measurement unit, obtaining first measurement information indicating a height of the measurement target region in each of a plurality of first measurement lines parallel to the first direction and different from each other by measuring each measurement line by the measurement unit, and while driving the measurement target region with respect to the measurement unit in a second direction crossing all of the plurality of first measurement lines, obtaining second measurement information indicating a height of the measurement target region in one second measurement line parallel to the second direction by measuring the second measurement line by the measurement unit.

The present invention provides a measurement method including while driving a measurement target region of a surface of a substrate in a first direction with respect to a measurement unit, obtaining first measurement information indicating a height of the measurement target region in each of a plurality of first measurement lines parallel to the first direction and different from each other by measuring each measurement line by the measurement unit, and while driving the measurement target region with respect to the measurement unit in a second direction crossing all of the plurality of first measurement lines, obtaining second measurement information indicating a height of the measurement target region in one second measurement line parallel to the second direction by measuring the second measurement line by the measurement unit.

Non-contacting caliper measurements of free standing sheets such as porous polymer and paper detect mid-IR interferometric fringes created by the reflection of light from the top and bottom surfaces of the sheet. The technique includes directing a laser beam at a selected angle of incidence onto a single spot on the exposed outer surface wherein the laser beam comprises radiation having a wavelength in the 3-50 micron range and scanning the laser beam through a selected angle range as the laser beam is directed onto the exposed outer surface and measuring the intensity of an interference pattern that forms from the superposition of radiation that is reflected from the exposed outer surface and from the inner surface. Thickness can be extracted from the fringe separation in the interference pattern. Rotating and focusing elements ensure that the spot position on the sheet remains the same while varying the incident angle.

The invention relates to a casting apparatus for the production of a cast sheet of homogenized tobacco material, said casting system comprising a casting box adapted to contain a slurry of the homogenized tobacco material; a movable support; a casting system adapted to deposit the slurry contained in the casting box onto the movable support so as to form the cast sheet; a sensor to detect a thickness of the cast sheet; wherein the sensor includes a slider comprising a planar surface adapted to be in contact to a top surface of the cast sheet and a height detector adapted to measure the height of the planar surface so as to derive the thickness of the cast sheet. The invention also relates to a method to measure the thickness of a homogenized tobacco sheet.

A method and a device for continuously detecting thickness of a sheet-type medium in a continuous conveying process can achieve a more accurate and stable detected thickness value. The device for detecting thickness of a sheet-type medium comprises a conveying roller; a detection roller, the detection roller being arranged opposite to the conveying roller, and an elastic displacement existing between the detection roller and the conveying roller; a plate spring, arranged by pressing opposite to the other side of the detection roller relative to the conveying roller; a sensor, arranged above the plate spring; and a thickness calculation unit, calculating a thickness value of the sheet-type medium according to a distance detection value and a standard zero value; and further comprises a zero value correction unit.

Non-contacting caliper measurements of free standing sheets such as porous polymer and paper detect mid-IR interferometric fringes created by the reflection of light from the top and bottom surfaces of the sheet. The technique includes directing a laser beam at a selected angle of incidence onto a single spot on the exposed outer surface wherein the laser beam comprises radiation having a wavelength in the 3-50 micron range and scanning the laser beam through a selected angle range as the laser beam is directed onto the exposed outer surface and measuring the intensity of an interference pattern that forms from the superposition of radiation that is reflected from the exposed outer surface and from the inner surface. Thickness can be extracted from the fringe separation in the interference pattern. Rotating and focusing elements ensure that the spot position on the sheet remains the same while varying the incident angle.

An automatic measuring apparatus includes a measuring device that measures a dimension of a workpiece, the measuring device including a movable element that is displaceable with respect to a fixed element and moves forward and backward to be brought into contact with or away from the workpiece, and a displacement detection part that detects a displacement or position of the movable element, and an automatic operation part that automates the forward/backward movement of the movable element by power. A workpiece holding part that holds the workpiece in such a manner that a position and posture of the workpiece is changed at a pressure lower than a predetermined measurement pressure set in advance in the measuring device when the movable element is brought into contact with the workpiece.