Devices are provided for indicating a moisture content of a substance such as soil. In an example, a device for indicating a moisture content of soil includes a stem configured to be inserted into the soil and an indicator coupled to the stem and configured to visually indicate the moisture content of the soil, the stem and the indicator each comprised of an absorbent material and at least the indicator including hydrochromic ink on the absorbent material.

Disclosed herein are sensors comprising a covalent organic framework (COF). The COF comprising a tautomerically active subunits (TAS) capable of reversible iminol-to-ketoenamine tautomerism between a first tautomer and a second tautomer and a inking group. Methods of detecting analytes with the sensors are also disclosed.

Disclosed herein are sensors comprising a covalent organic framework (COF). The COF comprising a tautomerically active subunits (TAS) capable of reversible iminol-to-ketoenamine tautomerism between a first tautomer and a second tautomer and a inking group. Methods of detecting analytes with the sensors are also disclosed.

The present invention relates to an apparatus for evaluating drying quality of an electrode, and the apparatus includes: an oven configured to provide a space in which an electrode is dried; a measuring unit configured to be positioned at an outlet of the oven and measure a color coordinate value of an electrode active material layer with respect to the dried electrode; and an determination unit configured to determine whether the electrode is dry from the color coordinate value, wherein the determination unit sets a reference value, and determines that a dry state of the electrode is defective if the measured color coordinate value is less than the reference value, and a difference between the measured color coordinate value and the reference value is more than a preset value.

A process of utilizing a water-sensitive fluorophore for moisture content evaluation in a hygroscopic polymer includes forming a blend that includes a hygroscopic polymer resin and a water-sensitive fluorophore. The process includes forming pellets having a particular geometry from the blend, determining fluorescence properties of at least one of the pellets, and determining moisture content of at least one of the pellets. The process also includes generating a calibration curve for the particular pellet geometry by correlating the fluorescence properties with the moisture content. The process further includes providing the calibration curve for non-destructive moisture content evaluation of a material derived from the pellets.

A process of utilizing a water-sensitive fluorophore for moisture content evaluation in a hygroscopic polymer includes forming a blend that includes a hygroscopic polymer resin and a water-sensitive fluorophore. The process includes forming pellets having a particular geometry from the blend, determining fluorescence properties of at least one of the pellets, and determining moisture content of at least one of the pellets. The process also includes generating a calibration curve for the particular pellet geometry by correlating the fluorescence properties with the moisture content. The process further includes providing the calibration curve for non-destructive moisture content evaluation of a material derived from the pellets.

A hydrophobic membrane structure includes: a color-changing layer, and a hydrophobic layer covering the surface of the color-changing layer. The color of an area of the color-changing layer in contact with the liquid changes to form a color-changing area, when the color-changing layer comes into contact with liquid.

A measurement apparatus (10) includes a generator (121) that irradiates electromagnetic waves on a measurement target (M) including a substance that undergoes a structural transition from a first substance with an unstable structure to a second substance with a stable structure due to entry of a foreign substance, a receiver (122) that receives the electromagnetic waves including information on a spectroscopic spectrum of the measurement target (M), and a controller (116) that acquires the measured spectroscopic spectrum based on the electromagnetic waves received by the receiver (122), calculates ratio information between the first substance and the second substance based on the acquired measured spectroscopic spectrum, and generates diagnostic information regarding entry of the foreign substance based on the ratio information.

A one-way relief valve for hermetically sealed packages is disclosed, wherein said valve comprises a valve body (100) made of a lower support surface (102) provided with vent holes (101) and a flexible membrane (110) associated with said lower support surface (102) that is capable of switching between a configuration in which the valve is closed and a configuration in which the valve is open. Said membrane (110) is characterised in that it is coloured, in order to facilitate visual inspection by the operator or the machine during the assembly of the valve and/or the production of hermetically sealed packages provided with the valve.

A soil moisture indicator contains a water-absorbing material and a color-changing part. A body part is formed and hollow by a material through which water does not pass, and has a water-absorbing opening proximate one end and a transpiration opening positioned near the other end. A display part is connected to the other end of the body part and allows an inner hollow portion to be viewed. An upper-end part that constitutes the end portion of the display part can be removed from and connected to the display part at the end portion on the opposite side to the end portion connected to the body. There is a change in color tone indication between a water-absorbed state and a dry state.