8 results about "Refractometry" patented technology

Methods and systems configured to measure content of a target substance in a fluid sample using a refractometer including a light source and a light sensor. A method includes: calibrating the refractometer by identifying a calibration pixel pattern of first pixels of the light sensor illuminated by light from the light source that has reflected off a sensing surface of a container including a reference fluid having a known reference density; identifying a blood pixel pattern of second pixels of the light sensor illuminated by light from the light source that has reflected off the sensing surface when the fluid sample is present in the container; identifying a pixel shift distance along the light sensor from the calibration pixel pattern to the fluid pixel pattern; and determining the content of the target substance in the fluid sample based on the pixel shift distance.

This invention belongs to the field of compound analysis and provides a method for detecting the content and isomer ratio of hydroxypropyltetrahydropyranotriol using high-performance liquid chromatography-differential refractive index (HPLC-DRI). The method includes the following steps: qualitative and quantitative analysis of prepared standard solutions and test solutions using HPLC-DRI. The method provided by this invention uses a simple and clean mobile phase with no impact on human health, simplifies sample pretreatment, has a low detection limit for hydroxypropyltetrahydropyranotriol, exhibits good linearity within the linear range, high correlation coefficient, high resolution of diastereomers, and good repeatability. It provides an effective detection method for ensuring the quality of hydroxypropyltetrahydropyranotriol and screening for superior grades.

A refraction measuring apparatus which measures the refractive properties of an eye by two light beams passing through two holes respectively, the apparatus comprising: a first rotating member rotatably supported around a first rotation center, equipped with two holes on either side of the first rotation center; a second rotating member rotatably supported around a second rotation center, equipped with light-transmitting portion(s) and light-blocking portion at different rotating direction positions. When the first rotating member rotates, the second rotating member rotates while the hole arrangement direction of the two holes changes with the rotation of the second rotating member, into a light-transmitting state in which the light-transmitting portion coincides with the two holes to allow the two light beams to pass through, or into a light-blocking state in which the light-blocking portion coincides with the two holes to shield the two light beams.

Objective refraction error measuring apparatuses are known. Once the measurement is done, there is no known method for confirming if the measurements are correct. Disclosed is an apparatus wherein once the error is measured, the determined values of the error are used to set the characteristics of a tunable lens so as to correct the error in the vision of the subject. The objective error is measured again while the subject viewing through the tunable lens so set. Objective refraction error is again measured. If the error measured is now within predefined limits, the first measurement is deemed correct and the values are out put so that glasses with those values may be prescribed to the subject.

The utility model relates to a refraction method saline concentration on-line analyzer, which comprises an explosion-proof analyzer controller and an explosion-proof field detection probe which are connected through a cable, the explosion-proof analyzer controller comprises a signal acquisition and processing module, a signal output module, a display and operation module, a control module and a power supply module, and circuit boards of the modules are arranged in a shell of the explosion-proof analyzer controller in a layered manner; the explosion-proof field detection probe comprises a prism, a high-intensity light source, a photoelectric conversion module, a temperature element, an automatic cleaning unit, a power supply and a signal acquisition and amplification circuit. The device disclosed by the utility model can be directly immersed in a sodium chloride solution for measurement and is not corroded by chloride salt liquid; compared with an original conductivity method, the refraction method for measuring the response time is shorter, the measurement precision is higher, and the stability is higher; the liquid receiving surface of the prism of the detection probe is obliquely arranged, so that the interference caused by the fact that bubbles entrained in the liquid adsorb the liquid receiving surface of the prism is effectively avoided; the analyzer has an automatic cleaning function, so that the accuracy and the stability of the analyzer are further guaranteed while a large amount of labor cost is saved.

Disclosed is a measuring apparatus for determining the concentration of constituents in a fluid, such as cooling lubricants or HFC hydraulic liquids, by refractometry, wherein the fluid present for measuring is guided through a sample chamber, which is connected to a fluid inlet and a fluid outlet and which is at least partially transparent such that the beams of a light source, for example in the form of a laser, passing through the sample chamber containing the fluid at least partially experience a refraction and can be detected by a sensor device outside the sample chamber.

Disclosed is method for determining the concentration of constituents in a fluid, such as cutting fluids or HFC fluids, using refractometry by means of a laser of a measuring device that uses the transmitted light principle, comprises specifying a peak value for the laser light received by refraction on a photodiode line using a homogeneous fluid to be transilluminated, and keeping the peak value constant despite the occurrence of disturbances by adapting one or more of the duty cycle of the laser, the current intensity for the laser, and the sensitivity of the photodiode line.

A method and system is provided that measures plasma protein levels of whole blood while a plasma donor is connected to an apheresis machine. A refractometer associated with the apheresis machine is capable of receiving a portion of a disposable tubing set including an integrated cuvette and prism. The integrated cuvette of the disposable tubing set can be inserted into a receiving space of the refractometer associated with the apheresis machine such that the light source and the sensor are oriented relative to the prism and a sensing surface of the integrated cuvette in a precise alignment. Calibration of the refractometer is made using anticoagulant pumped through the disposable tubing set including the integrated cuvette and prism. Based on a light intensity associated with this calibration, whole blood is then measured to determine plasma protein levels and donor eligibility.