Abstract:
An apparatus is disclosed that includes a circuit board. The circuit board includes a thermally conductive surface, an A/D converter having an internal temperature sensor, and a thermally conductive pad thermally coupled to the temperature sensor and the thermally conductive surface. The apparatus further includes a thermocouple having a reference junction thermally coupled to the thermally conductive pad and the thermally conductive surface.
Abstract:
A method is disclosed of determining a rate of decay of fluorescent light emitted from a photoluminescent material in operative communication with a substance having a property. The fluorescent light is emitted in response to stimulation of the photoluminescent material by a pulse of stimulation light. The rate of decay is correlated with a value of the property of the substance. The method includes receiving a data signal produced in response to receipt of the fluorescent light, and calculating a derivative of the data signal with respect to time to produce a derivative signal. The method also includes calculating the rate of decay from the derivative signal. Any offset in the data signal is eliminated by the calculating of the derivative.
Abstract:
A method is disclosed of determining a rate of decay of fluorescent light emitted from a photoluminescent material in operative communication with substance having a property. The fluorescent light is emitted in response to stimulation of the photoluminescent material by a pulse of stimulation light. The rate of decay is correlated with a value of the property of the substance. The method includes receiving a data signal produced in response to receipt of the fluorescent light, and applying a weighting function to the data signal to produce a weighted data signal. The method also includes calculating a rate of decay from the weighted data signal.
Abstract:
A method is disclosed that includes causing excitation of a fluorescent sensor and obtaining a measurement value from the fluorescent sensor at each of two times separated by a sampling interval. The method also includes determining a rate of change of the measurement values over the sampling interval. The method also includes, if the rate of change of the measurement values is greater than a first, upper threshold value, decreasing the sampling interval for subsequent excitations and measurements. The method also includes, if the rate of change of the measurement values is less than a second, lower threshold value, increasing the sampling interval for subsequent excitations and measurement.