To provide a solid-state light-receiving device for ultraviolet light which can measure the amount of irradiation with ultraviolet light harmful to the human body using a simplified structure and properly and accurately, which can be readily integrated with a sensor of a peripheral circuit, which is small, light-weight, and low-cost, and which is suitable for mobile or wearable purposes. One solution is a solid-state light-receiving device for ultraviolet light which is provided with a first photodiode (1), a second photodiode (2), and a differential circuit which receives respective signals based on outputs from these photodiodes, wherein a position of the maximum concentration of a semiconductor impurity is provided in each of the photodiodes (1,2) and in a semiconductor layer region formed on each photodiode, and an optically transparent layer having a different wavelength selectivity is provided on a light-receiving surface of each photodiode.

A system is provided for determining personal ultra-violet (UV) radiation measurements, comprising: a measurement device configured to measure UV irradiation; and a terminal device configured to receive or capture an output of the measured UV irradiation from the measurement device and to determine a specific user's personal UV exposure risk level based on at least the measured sun irradiation and information of a skin type of the specific user. The measurement device configured to measure UV radiation exposure includes a surface that includes a plurality of different sections that each have a different sensitivity to UV radiation exposure, and each of the plurality of different sections are configured to display a different color in response to the UV radiation exposure.

A lithographic apparatus including a monitoring apparatus and an associated monitoring apparatus. The monitoring apparatus is configured for monitoring first radiation of a first wavelength. The monitoring apparatus has a first sensor apparatus including a diamond fluorescent material configured to absorb the first radiation and to emit second radiation being representative of the first radiation, the second radiation being of a second wavelength; and a second sensor apparatus configured to sense the second radiation.

Provided an ultraviolet-sensing sheet that facilitates measurement of ultraviolet irradiance over a wide area, that is suitable in ultraviolet irradiance in a range from 1 to 1,000 mJ/cm.sup.2, a method for manufacturing such an ultraviolet-sensing sheet, and a method for sensing ultraviolet. The ultraviolet-sensing sheet has a change in reflection density D1 of 0.2 or more over a range of cumulative illuminance 1 mJ/cm.sup.2 or more and less than 10 mJ/cm.sup.2, a change in reflection density D2 of 0.2 or more over a range of cumulative illuminance 10 mJ/cm.sup.2 or more and less than 100 mJ/cm.sup.2, and a change in reflection density D3 of 0.2 or more over a range of cumulative illuminance 100 mJ/cm.sup.2 or more and 1,000 mJ/cm.sup.2 or less, as measured at a wavelength of 365 nm when the ultraviolet-sensing sheet is irradiated with a high-pressure mercury lamp.

An electronic device comprising: an ultraviolet (UV) light sensor; and a processor configured to: generate a plurality of initial UV light measurements by using the UV light sensor, wherein each of the plurality of initial UV light measurements is associated with a respective orientation of the electronic device; and select a reference UV light measurement from the plurality.

Provided is a solid-state light-receiving device for ultraviolet light, which is capable of measuring an irradiation amount of UV-rays, which are harmful to a human body, accurately and appropriately with a simple structure, and of being formed easily and integrally with sensors of peripheral circuits, and which is small, lightweight, low cost, and suitable for mobile or wearable applications. The solid-state light-receiving device for ultraviolet light includes a first photodiode, a second photodiode, and a differential circuit to which signals based on outputs of those photodiodes are input. The solid-state light-receiving device for ultraviolet light also includes semiconductor layer regions, which are formed in and on the above-mentioned photodiodes, and each of which includes a highest concentration position of semiconductor impurities.

A photodiode (2) and a further photodiode (3) are arranged in a substrate (1) at or near a main surface (10). The photodiodes are formed and arranged in such a manner that in case of incident ultraviolet radiation (26) the electric signal from the photodiode (2) is larger than the further electric signal from the further photodiode (3). In particular, the first photodiode may be more sensitive to ultraviolet radiation than the further photodiode. The electric signal from the photodiode is attenuated by the further electric signal and thus yields an electric signal primarily measuring the incident ultraviolet radiation. The attenuation of the electric signal from the first photodiode may be achieved internally using an integrated circuit (25) or externally using a separate device.

According to an embodiment, an ultraviolet (UV) irradiation apparatus includes a treatment tank, a UV irradiation member, a UV sensor, and an air outlet unit. The air outlet unit is connected to an air outlet hole provided at a position higher than a horizontal plane that passes through the UV sensor, and is provided to release, to the outside of the treatment tank, through the air outlet hole, air that accumulates inside the treatment tank when the treated waterlasses through the inside of the treatment tank.

A system capable of detecting and/or sterilizing surface(s) of an object using ultraviolet radiation is provided. The system can include a disinfection chamber and/or handheld ultraviolet unit, which includes ultraviolet sources for inducing fluorescence in a contaminant and/or sterilizing a surface of an object. The object can comprise a protective suit, which is worn by a user and also can include ultraviolet sources for disinfecting air prior to the air entering the protective suit. The system can be implemented as a multi-tiered system for protecting the user and others from exposure to the contaminant and sterilizing the protective suit after exposure to an environment including the contaminant.

Provided is a method and an apparatus for indicating minimum exposure of a surface to UVC light emitted by a source during a decontamination process to achieve a desired level of pathogen reduction. The apparatus includes a photochromic material to be applied to, or applied adjacent to the surface. The photochromic material is to exhibit a visible response to receiving the minimum exposure to the UVC light, and exhibit the visible response to a lesser extent after the photochromic material ceases to be exposed to the UVC light emitted by the source. A protective layer of material that is substantially transparent to the UVC light emitted by the source is positioned over the photochromic material to be disposed between the source and the photochromic material during the decontamination process.