A method to normalize at least one of a population of subordinate clinical diagnostic analyzer to a master clinical diagnostic analyzer such that an assay result from a subordinate clinical diagnostic analyzer can be converted to the equivalent result of the master clinical diagnostic analyzer by using a simple multiplicative factor when the assay executed on each analyzer uses a common fluorescently labeled dye. Also a method to re-normalize a subordinate clinical diagnostic analyzer assay result to a master clinical diagnostic analyzer assay result by using a simple multiplicative factor when the assay executed on the subordinate clinical diagnostic analyzer uses a different fluorescently labeled dye than the assay executed on the master clinical diagnostic analyzer.

Systems and methods for detecting a biological analyte are provided. The biological analyte can be, for example, cortisol. Detection can be achieved without external labels/mediators. Microfluidic systems can be incorporated into the optical sensor for enhanced point-of-care applications. The sensor can be used in a variety of low-power electronics for wearable applications.

One or more techniques and/or systems are provided for waste object detection. For example, a waste alert component is configured to emit ultraviolet light towards a waste detection zone, such as a bathroom floor or countertop. If a waste object, such as a paper towel or other object with a fluoresce property, exists within the waste detection zone, then the waste alert component may detect an increase in light due to the waste object fluorescing visible light in response to the ultraviolet light. If the increase in light intensity exceeds a detection threshold, then the waste alert component may provide a waste detection alert that the waste object exists within the waste detection zone (e.g., a message may be sent to a housekeeper that paper towel waste in on the bathroom countertop).

An optical sensor may be used to measure the concentration of calcium in a water sample, such as a water sample obtained from industrial process water system like a cooling tower system, a boiler water system, or a waste water system. To measure the concentration of calcium, an indicator or reagent may be added to the water sample to form a complex that absorbs light. The absorbance profile of the complex may be non-linear over a range of calcium concentrations. However, the absorbance profile can be linearized to provide calibration coefficients that are subsequently used to determine the concentration of calcium in samples having unknown calcium concentrations. The linearization of the absorbance profile can allow the optical sensor to be calibrated using two solutions. This can reduce the complexity and cost of calibrating the optical sensor, which may otherwise require at least three calibration solutions to capture the non-linear profile of the absorbance curve.

A multiparameter standard solution for verifying and calibrating water quality sensors containing an aqueous pH buffer, a xanthene dye, and distyryl biphenyl (DSBP) is provided. The standard solution provides a safe, quick, easy, and stable field standard to simultaneously conduct calibration analysis for several sensors at once. The standard solution is stable when stored and can be safely disposed of in the field. Methods of calibrating sensors used in water quality analysis using the multiparameter standard solution are also provided.

A calibration standard for determining an intensity decay related to an evanescent field generated close to the interface between a sample to be tested and a substrate on which the sample is to be deposited, preparation and analysis methods and use thereof.

The present disclosure discloses a method for calibrating a photometric analyzer which is designed to determine the silicate content of an analyte, comprising the steps of: detecting a first measurement point, with the steps of adding a first reagent to a sample of a first calibration standard, adding a second reagent to this sample, adding a third reagent to this sample; detecting a second measurement point, wherein the second measurement point differs from the first measurement point, with the steps of adding the second reagent to a sample of a second calibration standard, adding the first reagent to this sample, adding a third reagent to this sample; determining the zero point and the slope of the calibration line using the first and second measurement points.

A method for quantifying a crude oil in water is provided. The method includes selecting an ultraviolet/visible (UV/Vis) wavelength to perform a measurement, preparing calibration solutions in xylene, and preparing a calibration curve from the calibration solutions. A sample is prepared including extracting the crude oil from the water in a two-phase separation with xylene. An absorbance of the sample in the xylene is measured at the UV/Vis wavelength. A concentration of the crude oil in the water is calculated from the absorbance.

There is provided a method of calibrating a sensor comprising a luminescent compound having a luminescence that depends on the concentration of an analyte, and a detector configured to detect light emitted by the luminescent compound, the method comprising providing a component comprising the luminescent compound in a package that maintains exposure of the luminescent compound to the analyte at a known first concentration, assembling the component into the sensor and measuring a first value of a characteristic of the luminescence of the luminescent compound while exposed to the analyte at the first concentration, measuring a second value of the characteristic of the luminescence of the luminescent compound while exposed to the analyte at a known second concentration different from the first concentration, and determining parameters representing the dependence of the characteristic of the luminescence on concentration of the analyte using the first value and the second value.

A method and system for calibrating a PET scanner are described. The PET scanner may have a field of view (FOV) and multiple detector rings. A detector ring may have multiple detector units. A line of response (LOR) connecting a first detector unit and a second detector unit of the PET scanner may be determined. The LOR may correlate to coincidence events resulting from annihilation of positrons emitted by a radiation source. A first time of flight (TOF) of the LOR may be calculated based on the coincidence events. The position of the radiation source may be determined. A second TOF of the LOR may be calculated based on the position of the radiation source. A time offset may be calculated based on the first TOF and the second TOF. The first detector unit and the second detector unit may be calibrated based on the time offset.