US 6,633,035 B1Granted

Water content-measurement method and water content-measurement apparatus, and electrical component-fabrication method using the measurement apparatus and method

AssigneeHitachi, Ltd.

InventorsJunichi Katagiri, Yoshitaka Takezawa, Yuzo Ito

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Abstract

A measurement method and apparatus, which are capable of simply measuring the water content of an object with a high degree of accuracy, is characterized by irradiating the surface of the object with at least two monochromatic light beams having different wave length values, one of the wave length values being less than 1350 nm; measuring the intensity of light for each of the light beams reflected from the surface of the object using a light intensity-measurement unit; obtaining the reflective absorbance (Aλ) of each light beam; calculating a reflective-absorbance differences (ΔAλ) between, or a reflective-absorbance ratio (Aλ′) of, the respective light beams, respectively; and estimating the water content of the measured object by using the relationship between water content and the reflective-absorbance differences or reflective-absorbance ratio, which relationship stored in a memory device in advance.

Claims5

Dependent claims

A method of fabricating an electrical component in which a coil conductor covered with an insulating paper is contained in a case, and insulation oil is poured into said case after said coil conductor covered with the insulating paper is dried, said method comprising:

irradiating a surface of said insulating paper with at least two kinds of monochromatic light beams of different wave length values λ1 and λ2, one of said wave length values being less than 1350 nm, said light beams being led to said surface of said insulating paper by a light-guiding device for light-irradiation;
measuring an intensity of light in each of the light beams which is reflecting from said surface of said insulating paper by leading said reflected light to a light intensity-measurement unit using a light-guiding device for light-receive;
obtaining reflective absorbance (Aλ) of each light beam using equation (1);
calculating a reflective-absorbance difference (ΔAλ) between, or a reflective-absorbance ratio (Aλ′) of, said respective light beams using equation (2) or (3), respectively;
estimating water content of said coil conductor covered with said insulating paper by using said calculated reflective-absorbance difference (ΔAλ) or said calculated reflective-absorbance ratio (Aλ′), and relationship between water content and reflective-absorbance differences (ΔAλ) or reflective-absorbance ratios (Aλ′), said relationship being memorized in a memory device in advance;
drying said coil conductor covered with said insulating paper until said water content of said coil conductor becomes less than a predetermined value;
and
pouring insulation oil into the case;
wherein, Aλ=−log (Iλ/I0,λ) (1)
ΔAλ=Aλ1−Aλ2 (here, λ1>λ2) (2), and
Aλ′=Aλ1/Aλ2 (here, λ1>λ2) (3),
where I:
intensity of light reflecting from a surface of a standard white board, I0:
said intensity of said light reflecting from said surface of said measured object member, and λ2:
a wave length value less than 1350 nm.

12 more elements

A method of fabricating an electrical component in which a stator core is wound by a coil conductor covered with a insulating paper, and a varnishing process is performed for said stator core and said coil conductor after said stator core wound by said coil conductor covered with said insulating papers is dried, said method comprising:

irradiating a surface of said insulating paper with at least two kinds of monochromatic light beams of different wave length values λ1 and λ2, one of said wave length values being less than 1350 nm, said light beams being led to said surface of said insulating paper by a light-guiding device for light-irradiation;
measuring an intensity of light in each of the light beams which is reflecting from said surface of said insulating paper by leading said reflected light to a light intensity-measurement unit with a light-guiding device for light-receive;
obtaining reflective absorbance (Aλ) of each light beam using equation (1);
calculating a reflective-absorbance difference (ΔAλ) between, or a reflective-absorbance ratio (Aλ′) of, the respective light beams using equation (2) or (3), respectively;
estimating water content of said coil conductor covered with said insulating paper by using said calculated reflective-absorbance difference (ΔAλ) or said calculated reflective-absorbance ratio (Aλ′), and relationship between water content and reflective-absorbance differences (ΔAλ) or reflective-absorbance ratios (Aλ′), said relationship being memorized in a memory device in advance;
drying said coil conductor covered with said insulating paper until said water content of said coil conductor becomes less than a predetermined value;
and
performing a varnishing process for said stator core and said coil conductor;
wherein, Aλ=−log (Iλ/I0,λ) (1),
ΔAλ=Aλ1−Aλ2 (here, λ1>λ2) (2), and
Aλ′=Aλ1/Aλ2 (here, λ1>λ2) (3),
where I:
intensity of light reflecting from a surface of a standard white board, I0:
said intensity of said light reflecting from said surface of said measured object member, and λ2:
a wave length value less than 1350 nm.

12 more elements

Dependencies are inferred from the claim text.