1184 results about "Optical absorbance" patented technology

A sample element includes first and second substantially parallel faces separated by an intermediate member. The parallel faces and the intermediate member at least partially define a sample chamber configured to hold a volume of fluid. The sample element further includes an optical path extending through the parallel faces and the intermediate member, such that electromagnetic radiation can propagate through the sample chamber. The sample element further includes an identifying compound disposed within or on at least one of the parallel faces. The identifying compound has at least one indexed optical absorbance feature, such that spectral analysis of electromagnetic radiation propagated through the sample chamber yields the indexed optical absorbance feature. Detection of the indexed optical absorbance feature in electromagnetic radiation propagated through the sample chamber indicates to an analyte detection system whether the sample element is configured for use with the analyte detection system.

Provided are photochromic articles including a substrate, a primer layer that includes a first photochromic compound, and a photochromic-dichroic layer over the primer layer that includes a photochromic-dichroic compound. The first photochromic compound and the photochromic-dichroic compound each are selected such that the photochromic-dichroic compound has an unactivated state terminal minimum absorbance wavelength that is less than or equal to the unactivated state terminal minimum absorbance of the underlying first photochromic compound. The present invention also relates to such photochromic articles that further include a topcoat layer over the photochromic-dichroic layer, the topcoat layer including a second photochromic compound that has an unactivated state terminal minimum absorbance wavelength that is less than the unactivated state terminal minimum absorbance wavelength of the underlying photochromic-dichroic compound.

A fiber optic probe for ATIR (Attenuated Total Internal Reflection) spectrophotometry. The probe includes a housing that contains an optical element or lens, a light-transmitting fiber that directs incident light to the lens, a light-receiving fiber that receives reflected light from the sample interface, a coupler for holding these components in precise alignment, and a flexible armor casing that provides strain relief and protection for the optical fibers. The lens is shaped and dimensioned so that light from the transmitting fiber is reflected at the interface between the lens and the surrounding medium (such as a liquid to be analyzed). The reflected light is transmitted via the transmitting fiber to a suitable spectrophotometer, where the light signal is recorded and analyzed to determine the composition of the sample. The probe is particularly suitable for analyses of fluids and slurries with high optical absorbance.

Impurity is removed from gas, the resultant gas is introduced into a cell 15, and the intensity of light transmitted through the cell 15 is measured as a reference. Gas containing impurity of which concentration is known, is introduced into the cell 15, and the intensity of light transmitted through the cell 15 is measured with the temperature and pressure maintained at those used at the measurement of the reference light intensity. Then, the absorbance of the impurity is obtained according to the ratio of the two light intensity data obtained by the two measurements above-mentioned. The impurity absorbance thus obtained is stored, in a memory 20a, as a function of an impurity concentration. Gas containing impurity of which concentration is unknown, is introduced into the cell 15, and the intensity of light transmitted through the cell 15 is measured with the temperature and pressure maintained at those used at the measurements above-mentioned. The absorbance of the impurity is obtained according to the last-measured light intensity and the reference light intensity. The absorbance thus obtained is applied to the function, thereby to obtain the impurity concentration.

Provided are a toner containing at least a binder resin and a colorant, the toner having a specific hue angle and an absorbance at a specific wavelength in reflectance spectrophotometry, and a full-color image-forming method involving the use of the toner, the method including the steps of: forming an electrostatic image on a charged electrostatic image bearing member; developing the formed electrostatic image with the toner to form a toner image; transferring the formed toner image onto a transfer material; and fixing the transferred toner image to the transfer material to form a fixed image.

The invention discloses a low-concentration, multi-component and high-sensitivity gas detection method based on integration of multiple spectrum technologies. Advantages of an ultraviolet differential optical absorption spectroscopy (DOAS) technology and an infrared tunable diode laser absorption spectroscopy (IR-TDLAS) technology are integrated, so that information integration and characteristic signal extraction of two kinds of spectrum are realized. The method disclosed by the invention is used for measuring the NH3 concentration in smoke by utilizing a TDLAS method and simultaneously measuring the concentrations of SO2 and NO2 in smoke by utilizing an ultraviolet DOAS method; interference of three components in the NO absorbancy is removed according to the obtained concentrations and an interference spectrum of three kinds of gas to the NO absorbancy, so that the NO concentration without cross interference is solved; and thus, the measurement precision and the detection lower limit are greatly increased.

A method and apparatus that allows accurate spectrophotometric determination of the concentrations of various hemoglobin species in whole undiluted blood. The invention employs 1) an optical apparatus designed to maximize the true optical absorbance of whole blood and to minimize the effects of light scattering on the spectrophotometric measurements of the concentrations of various constituent components, and 2) methods to correct the hemoglobin concentration measurements for light scattering and for the effects of the finite bandwidth of the substantially monochromatic light. In the optical apparatus optical parameters, such as sample thickness, detector size and shape, sample-to-detector distance, wavelengths, monochromicity, and maximum angle of light capture by detector, are selected so as to minimize the contribution of light scattering to maximize the contribution of true optical absorbance. After making measurements of a blood sample's optical density at each of the wavelengths, corrections are made for the effects of light scattering.

A method and apparatus for measuring and calibrating the measurement of small volumes of liquids. The small volumes of liquid are typically dispensed from liquid delivery devices, the delivery device often having multiple channels to analyze many samples at once. The liquid samples are delivered to one or more cells, typically in a multi-well plate, and positioned in a spectrophotometer for determining an absorbance of a chromophore in the liquid sample. Based upon an absorbance measurement and the concentration of the chromophore, a path length of the liquid sample is determined, from which a volume of the sample may be calculated. The method and apparatus provide various means for correcting for differences in the dimensions and/or other factors causing a non-linear deviation from the Beer-Lambert law. A system or kit may be provided including sets of sample solutions of varying dilution ranges for calibrating different liquid volumes. The kit may further include software code for storing and analyzing the various sample solutions.

It is an optical absorption ratio difference continuous flow determination trace amounts copper ion method, relating to a continuous flow analysis and optical absorption ratio difference linked water samples determination trace amounts copper ion concentration method. Prepare 0.04mmol/l chromium naphthalene green G and pH 4~5 acetate - sodium acetate buffer solution mixture as color solution; use peristaltic pump, mixed reactor, circulation pool an spectrophotometer to determine the water sample. The peristaltic pump uses 1000r/min speed to pump simultaneously the copper ion samples and color solution into a self-designed mixed reactor, and passing through the circulation pool, using the spectrophotometer to measure the copper ion sample concentration of 0-0.0180mg/l scope and 508nm wavelength and 586nm absorbance, to calculate the absorbance ratio, and draw the line; use the same method to determine absorbency of measured water samples; compare the line to calculate the copper ions concentration in water sample. The invention is fast, efficient and reproducible, and it can be online monitoring and continuous determination. It is suitable for rapid determination and online analysis for trace copper ions in drinking water, surface water, and other natural waters.

The invention provides a method for determination of a concentration of mineral oil mist in workshop air. The method comprises the following steps of collecting an oil mist sample form air by an ultrafine glass fiber membrane, carrying out extraction by 10mL of CCl4, directly carrying out detection by an infrared spectrophotometer by scanning in a range of 2700 to 3200cm<-1> to obtain the maximum absorption peak as a sample measurement wave number, and subtracting the absorbance at the wavelength of 3200cm<-1> from the absorbance of the maximum absorption peak to quantify a concentration of mineral oil mist in the oil mist sample. The method is accurate and fast, produces a small interference, has high sensitivity, precision less than 10%, accuracy less than 10% and a detection limit of 2.0 microgrammes per milliliter, and satisfies detection and research requirements. The method provided by the invention fills in the blank of infrared spectrophotometry-based determination of mineral oil mist in workshop air.