Processes, compositions, and sensors for sensing a variety of toxic chemicals based on colorimetric changes. Exemplary process for sensing a toxic chemical includes contacting a toxic chemical, or byproduct thereof, with a sorbent that includes a porous metal hydroxide or a porous mixed-metal oxide/hydroxide and a transition metal reactant suitable to react with a toxic chemical or byproduct thereof. The sorbent is contacted with the toxic chemical or byproduct thereof for a sampling time. A difference between a post-exposure colorimetric state of the sorbent and a pre-exposure colorimetric state of the sorbent is determined to thereby detect exposure to, or the presence of, the toxic chemical or byproduct thereof.

Processes, compositions, and sensors for sensing a variety of toxic chemicals based on colorimetric changes. Exemplary process for sensing a toxic chemical includes contacting a toxic chemical, or byproduct thereof, with a sorbent that includes a porous metal hydroxide or a porous mixed-metal oxide/hydroxide and a transition metal reactant suitable to react with a toxic chemical or byproduct thereof. The sorbent is contacted with the toxic chemical or byproduct thereof for a sampling time. A difference between a post-exposure colorimetric state of the sorbent and a pre-exposure colorimetric state of the sorbent is determined to thereby detect exposure to, or the presence of, the toxic chemical or byproduct thereof.

A sensor product for detecting an analyte or condition. The sensor product having a body and a circuit integrated with the body. The circuit including an electric power source, a sensing element comprising graphene or a graphene derivative in which the sensing element is configured to undergo a change in an electrical property in the presence of an analyte or condition, and an indicator configured to display information indicating the presence of the analyte or condition when the change in an electrical property of the sensing element occurs. For instance, the indicator may display “DANGER EVACUATE” in the presence of chlorine gas, elevated temperatures, or other analytes or conditions.

Systems and methods for sanitizing pool and spa water are provided. An electrolytic chlorinator is provided which includes a combined flow, temperature, and salt concentration sensor. The electrolytic chlorinator could include an acid tank for in-situ cleaning of the electrolytic chlorinator or acidification of pool/spa water where needed. A delayed polarity reversal technique is provided for de-scaling and managing passivation of the blades of an electrolytic chlorinator. The electrolytic chlorinator could include a sacrificial anode for protecting components of the chlorinator as well as other pool/spa components. The electrolytic chlorinator could include an integral, electrically-controlled acid generator, a brine tank for periodically superchlorinating and/or shocking pool/spa water, and/or a plurality of chemical tanks/feeds for periodically injecting chemicals into the chlorinator. A combined ultraviolet (UV)/Ozone and salt (electrolytic) chlorine generator is provided, as well as: filters having integral UV sanitizers; reflective linings for UV sanitization systems; means for injecting bubbles into pool/spa water; and a system for acquiring and analyzing samples of pool/spa water using an unmanned aircraft (drone).

A gas detection fuse comprising a thin strip or sheet of a conductive material, such as a metal, connecting two electrodes for detecting a gas of interest. The metal is selected to be reactive with the gas of interest, and has a relatively large surface area, such that when the gas of interest contacts the metal, the electrical connection between the electrodes is broken (e.g., due to the metal losing physical integrity, or becoming non-conductive, as a result of the reaction with the gas). The gas of interest may be chlorine, and the conducting material may be tin. When the tin is exposed to chlorine the tin becomes oxidized to produce liquid tin tetrachloride, thus breaking the electrical connection.

Systems and methods for sanitizing pool/spa water are provided. An electrolytic chlorinator is provided which includes a combined flow, temperature, and salt concentration sensor. The electrolytic chlorinator could include an acid tank for in-situ cleaning of the electrolytic chlorinator or acidification of pool/spa water where needed. A delayed polarity reversal technique is provided for de-scaling and managing passivation of the blades of an electrolytic chlorinator. The electrolytic chlorinator could include a sacrificial anode for protecting components of the chlorinator as well as other pool/spa components. The electrolytic chlorinator could include an integral, electrically-controlled acid generator, a brine tank for periodically superchlorinating and/or shocking pool/spa water, and/or a plurality of chemical tanks/feeds for periodically injecting chemicals into the chlorinator. A combined ultraviolet (UV)/Ozone and salt (electrolytic) chlorine generator is provided, as well as: filters having integral UV sanitizers; reflective linings for UV sanitization systems; means for injecting bubbles into pool/spa water.

The present invention provides a catalytic conversion-type sensor that detects a detection target gas by detecting a conversion gas produced through a reaction, the catalytic conversion-type sensor including: a gas flow path that allows the detection target gas to flow down; and a conversion portion that is connected to the gas flow path, the conversion portion including, on a side partitioned by a diffusion means that allows the detection target gas to naturally diffuse, a heated catalyst portion that produces a conversion gas by causing the detection target gas to come into contact with a heated catalyst and react with the heated catalyst, and a sensor element portion that is capable of detecting the conversion gas produced through the reaction.

A gas detector comprises: plural gas sensors provided with a metal-oxide semiconductor whose resistance changes based upon contact with a gas; and a driving circuit for operating the gas sensors. The gas detector stores the ratio between initial resistance in air of the metal-oxide semiconductor and initial resistance of the metal-oxide semiconductor in an atmosphere including a predetermined concentration of fron gas, for the plural gas sensors. The gas detector learns resistance in air of the metal-oxide semiconductor in a gas sensor in use, and detects occurrence of fron gas when resistance of the metal-oxide semiconductor of the gas sensor in use becomes lower than a value corresponding to the learned resistance in air divided by the ratio. The gas detector counts the period that a first gas sensor is used. When the first gas sensor has been used for a predetermined period, both the first gas sensor and a second gas sensor are used for a learning period to continue detection of fron by the first gas sensor and to learn the resistance in air of the metal-oxide semiconductor of the second gas sensor. After completion of the learning period, fron leakage is detected by the second gas sensor.

A gas detection fuse is provided, comprising a thin strip or sheet of a conductive material, such as a metal, connecting two electrodes for detecting a gas of interest. The metal is selected to be reactive with the gas of interest, and has a relatively large surface area, such that when the gas of interest contacts the metal, the electrical connection between the electrodes is broken (e.g., due to the metal losing physical integrity, or becoming non-conductive, as a result of the reaction with the gas). The gas of interest may be chlorine, and the conducting material may be tin. When the tin is exposed to chlorine the tin becomes oxidized to produce liquid tin tetrachloride, thus breaking the electrical connection.

An apparatus includes: a gas maintenance system having a gas supply system fluidly connected to one or more gas discharge chambers; a detection apparatus fluidly connected to each gas discharge chamber; and a control system connected to the gas maintenance system and the detection apparatus. The detection apparatus includes: a vessel defining a reaction cavity that houses a metal oxide and is fluidly connected to the gas discharge chamber for receiving mixed gas including fluorine from the gas discharge chamber in the reaction cavity, the vessel enabling a reaction between the fluorine of the received mixed gas and the metal oxide to form a new gas mixture including oxygen; and an oxygen sensor fluidly connected to the new gas mixture to sense an amount of oxygen within the new gas mixture. The control system is configured to estimate a concentration of fluorine in the received mixed gas.