Fluid measurement method, fluid measurement device, and measurement system

A measurement device for visualizing a flow of a fluid in which a photochromic compound is dissolved, the photochromic compound having an amount of absorption of light in a specific wavelength range that changes upon irradiation with transformation-inducing light that causes photochromism, the measurement device comprising:

• first image storage configured to store a first image taken of the fluid by using first light in a first wavelength range in which the amount of absorption changes;
• second image storage configured to store a second image of the fluid that is taken at the same time as the first image is taken, the taking of the second image using second light in a second wavelength range in which the amount of absorption does not change or hardly changes;
• and
• an image processor configured to generate a third image on which the flow of the fluid is visualized by using the first image and the second image, wherein
• the image processor generates a third image by using the first image and the second image that are taken after the fluid is irradiated with the transformation-inducing light.

A measurement device for measuring a thickness of a fluid in which a photochromic compound is dissolved, the photochromic compound having an amount of absorption of light in a specific wavelength range that changes upon irradiation with transformation-inducing light that causes photochromism, the measurement device comprising:

• first image storage configured to store a first image taken of the fluid using first light in a first wavelength range in which the amount of absorption changes;
• second image storage configured to store a second image of the fluid that is taken at the same time as the first image is taken, the taking of the second image using second light in a second wavelength range in which the amount of absorption does not change or hardly changes;
• and
• a fluid thickness calculator configured to calculate a thickness of the fluid by using the first image and the second image, wherein
• the fluid thickness calculator calculates a thickness of the fluid by using the first image and the second image that are taken after the fluid is irradiated with the transformation-inducing light.