Water hardness sensor system
A sensor including a substrate and a sensing element disposed on a substrate is provided. The sensing element includes a sensing matrix in contact with a flow of water, an indicator for one or more chemical species in the flow of water, and a selectivity component that reacts reversibly with the one or more chemical species. The sensor also includes a light source configured to direct light through the substrate and the sensing element. The sensor further includes a light detector configured to receive transmitted light from the substrate and the sensing matrix and to generate a signal representative of selective wavelengths of the light indicative of the one or more chemical species in the flow of water.
1. A sensor comprising:
a substrate;
a sensing element disposed on the substrate, the sensing element consisting of a single layer and including a sensing matrix, an indicator for one or more chemical species in a flow of water, and a selectivity component that reacts reversibly with the one or more chemical species, the sensing matrix being in contact with the flow of water during operation;
a light source configured to direct light through the substrate and the sensing element; and
a light detector configured to receive transmitted light from the substrate and the sensing matrix and to generate a signal representative of selective wavelengths of the light indicative of the one or more chemical species in the flow of water.
2. The sensor of claim 1 , wherein the selectivity component comprises a modifier that adjusts internal pH of the sensing element.
3. The sensor of claim 1 , wherein the selectivity component comprises a chelator to selectively alter response of the sensing element towards a specific chemical species.
4. The sensor of claim 3 , the chelator comprising 8-hydroxyquinoline.
5. The sensor of claim 1 , wherein the substrate comprises a polymer or glass.
6. The sensor of claim 1 , the indicator comprising at least one of calmagite, eriochrome black T, xylidyl blue or murexide.
7. The sensor of claim 1 , the one or more chemical species comprising calcium and magnesium.
8. The sensor of claim 1 , the sensing matrix comprising at least one of sol-gel, a polymer or a hydrogel.
9. The sensor of claim 1 , the sensor configured to measure multiple wavelengths of light.