CPC G01N 29/11 (2013.01) [G01B 17/02 (2013.01); G01N 29/36 (2013.01)] | 13 Claims |
1. A device comprising:
a sensor including an emission unit which emits ultrasonic waves and a reception unit which receives the ultrasonic waves, the emission unit and the reception unit being arranged opposite each other across a conveyance path through which a recording material is conveyed;
an instruction unit configured to input, to the emission unit, a first drive input for causing the emission unit to emit ultrasonic waves with a first maximum amplitude and a second drive input for causing the emission unit to emit ultrasonic waves with a second maximum amplitude larger than the first maximum amplitude; and
a detection unit configured to detect information about a grammage of the recording material based on a first value obtained by the reception unit receiving ultrasonic waves emitted from the emission unit with the first drive input supplied thereto and coming not through the recording material and a second value obtained by the reception unit receiving ultrasonic waves emitted from the emission unit with the second drive input supplied thereto and coming through the recording material.
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