US 12,442,809 B2
Hygroscopicity evaluation method and water content evaluation method
Tetsuya Uchida, Hamamatsu (JP); Kouichiro Akiyama, Hamamatsu (JP); Hiroshi Satozono, Hamamatsu (JP); and Tomoyuki Hakamata, Hamamatsu (JP)
Assigned to HAMAMATSU PHOTONICS K.K., Hamamatsu (JP)
Filed by HAMAMATSU PHOTONICS K.K., Hamamatsu (JP)
Filed on Jan. 11, 2023, as Appl. No. 18/095,575.
Claims priority of application No. 2022-020200 (JP), filed on Feb. 14, 2022; and application No. 2022-133126 (JP), filed on Aug. 24, 2022.
Prior Publication US 2023/0258620 A1, Aug. 17, 2023
Int. Cl. G01N 33/24 (2006.01); G01N 21/3581 (2014.01); G01N 21/552 (2014.01)
CPC G01N 33/246 (2013.01) [G01N 21/3581 (2013.01); G01N 21/552 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A hygroscopicity evaluation method for evaluating hygroscopicity of a measurement target object containing a clay mineral, comprising:
a first step of preparing a first sample containing a first clay mineral as the clay mineral and a second sample containing a second clay mineral, which is the same as the first clay mineral, as the clay mineral;
a second step of acquiring a first detection result for the first sample by making a first terahertz wave incident on the first sample and detecting the first terahertz wave from the first sample and a second detection result for the second sample by making a second terahertz wave incident on the second sample and detecting the second terahertz wave from the second sample; and
a third step of evaluating the hygroscopicity of the measurement target object based on a first frequency characteristic of the first sample calculated from the first detection result and a second frequency characteristic of the second sample calculated from the second detection result,
wherein, in the first step, at least one of the first and second samples is subjected to a water absorption/dehydration treatment to prepare samples having different hygroscopicity, and
in the third step, a magnitude of the hygroscopicity of the measurement target object is evaluated based on a difference between a magnitude of a first peak of the first frequency characteristic in a reference frequency range and a magnitude of a second peak of the second frequency characteristic in the reference frequency range.