Compositions, kits, and methods of using the kits and compositions to determine the hardness of and/or magnesium concentration in a solution are described. The kit can include a lyophilized composition that has an absorbance at a detectable wavelength in response to the hardness of the solution and or the concentration of magnesium in the solution.

A device to extract a near continuous stream of sample water from a high solids content source for the purpose of delivery to a liquid analyzer or sensor for test or measurement. The device includes a source of compressed air and a source of chemical cleaning agent that are used in a coordinated effort to purge and clean the sampling system to ensure the water stream is maintained over long periods of time without significant human intervention. The device includes a valve to allow compressed air to intermittently be sent backwards through the sampling line to purge to drain an inline strainer of solids that have built up since the previous air purge. Downstream of the air valve another valve is used to introduce cleaning chemical into the sampling system to clean residual buildup downstream of the inline strainer. A debubbler unit is placed between the air valve and the cleaning chemical valve to remove air from the sampling system after it was introduced during the air purge event.

A water hardness detection probe, sensor, detection method and water softener are provided. The sensor includes a control unit which includes a processing module and a potential detection module. The detection probe includes a first probe and a second probe. When the first and second probes are both exposed in raw water, a potential between the first and second probes is regarded as first potential. When the first probe is in the raw water and the second probe is in softened water, the potential between the first and second probes is regarded as the second potential. The potential detection module measures the potential between the first and second probes. The processing module determines the water hardness of the softened water according to a difference between the first potential and the second potential. The sensor can detect the water hardness of the water softener in real time and eliminate detection deviations.

An embodiment provides a method for stirring a sample in a cell, including: providing a cell comprising a sample chamber; placing a boron-doped diamond electrode on an inner surface of the sample chamber, placing a removable stir bar in the sample chamber, the removable stir bar directly contacting and touching the boron-doped diamond electrode; and wherein the stir bar can be operated to rotate within the sample chamber upon the boron-doped diamond electrode. Other aspects are described and claimed.

An appliance, system, and method for operating an appliance and determining presence of water softener at water provided to an appliance is provided. The system is configured to obtain a first water hardness value; obtain a second water hardness value based on a location of the appliance; determine a ratio of the first water hardness value and the second water hardness value; compare the ratio of the first water hardness value and the second water hardness value to a threshold limit; transmit a first water hardness signal when the threshold limit is exceeded, wherein the first water hardness signal corresponds to the first water hardness value; transmit, to the database storage device, a second water hardness signal when the ratio is within the threshold limit; and adjust operation of the appliance based on whether the first water hardness signal or the second water hardness signal is transmitted.

An indicator composition can be used to measure calcium hardness within a sample of water from a process water system. The indicator composition can include a calcium indicator, a range extender, and a buffer. The indicator composition can accurately measure calcium concentrations within the sample of water at low, moderate, and high calcium levels, including at calcium concentrations of greater than 50 ppm. The indicator composition can measure calcium hardness without the use of masking agents at a pH of less than about 7.

An apparatus for determining total hardness in a fluid stream utilizing a first and second sodium ion selective electrode (ISE). The ion selective electrodes are in electrical communication with one another, having first and second reference electrodes, respectively, with a salt bridge therebetween, where the first ISE receives hard water and the second ISE receives soft water. A least one drain receives outflow from effluent fluid from the first and second sodium ISE sensors.

A method of application to provide a workable solution for tracking the hardness of water utilizing an ion selective electrode by tracking the relative hardness of water at the outflow or egress of an ion exchange column. A monovalent cation exchange membrane (ion selective electrode) distinguishes hard water and softened water in a water flow stream. A voltage is applied across the membrane, facilitating the movement of sodium though the membrane (such that anions and divalent ions are excluded), and the current is measured. The change in current (delta current) is used to determine the hard water concentration or level of hardness in an influent stream. A second application estimates or detects the exhaustion of an ion exchanger, and/or determines the regeneration time/cycle of the ion exchanger through the use of an ion selective membrane. Blending of the influent hard water and effluent soft water allows a user to control hardness levels of the effluent.

An apparatus for determining total hardness in a fluid stream utilizing an ion exchange column in a monovalent cationic form having an inlet and an outlet, where one or more monovalent ion selective electrodes are positioned either at an inlet, outlet, or at both locations simultaneously. The monovalent cation selective electrodes are in electrical communication with one another, and in fluid communication with one or more valves incorporated within a fluid path in order to introduce feed water/softened water to the monovalent cation selective electrodes. Additionally, one blending valve may be incorporated in the ion exchange column to allow a fraction of the feed (hard) water to mix with a fraction of the softened water. In this manner, the blending valve may be utilized to adjust the hardness of the water at the output.

With respect to atmospheric steam generating humidifiers, the present disclosure resolves the problem of end-users not adjusting the drain interval of the humidifier by using an electronic controller to automatically choose an appropriate drain interval without requiring any user input. The electronic controller accomplishes this by receiving input data from a sensor that measures a water quality parameter, automatically determining a drain interval based on the received data, and sending an output control signal to a drain water control valve to execute a drain event in accordance with the drain interval. In some examples, the electronic controller utilizes a look-up table correlating the water quality parameter to a total dissolved solids or cycles of concentration value.