Abstract:
The invention relates to a method and apparatus for temperature compensation in gas analyzer equipment for transient error caused by temperature change. According to the method, a radiation source (1) is used for transmitting electromagnetic radiation through a gas mixture to be analyzed, the intensity of radiation transmitted through the gas mixture being analyzed is detected by means of a thermal detector (4) comprising a radiation detecting sensor element (16) and a reference sensor element (17) for generating an output signal proportional to the concentration of gas being analyzed, the temperature of said thermal detector (4) is measured either directly or indirectly, the measured detector temperature values are recorded as a function of time, and the output signal of the thermal detector (4) is temperature compensated by a correction term dependent on the temperature rate of change (DT) of the thermal detector. According to the invention, the uncorrected output signal V.sub.mass of the thermal detector (4) is temperature compensated by adding a correction term V.sub.comp dependent on the temperature rate of change (DT) of the thermal detector to said output signal.
Abstract:
Method and apparatus for the spectrophotometric assay of aqueous liquids are provided with a pump for aspirating liquids, a filter with two outlets for filling a cell in which the interferometric measurements are made at a temperature between 35 and 50.degree. C. at a maximum fluctuation of 0.2.degree. C., and with a maximum relative humidity of 0.2%. Absorption curves A(f) are determined with respect to a matrix and the concentrations of components to be assayed are calculated by the use of standard equations.
Abstract:
A colorimeter for characterizing the color of an object is placed in an environmentally sealed enclosure for use in industrial environments. In order to maintain an acceptable operating temperature for the colorimeter's electronics and lamp, a heat shield is placed around the lamp to substantially isolate it from the electronics. The heat shield and the environmentally sealed enclosure are made of a highly heat conductive material such as aluminum. The heat shield is thermally coupled to the environmentally sealed enclosure.
Abstract:
An automatic chemical analyzer for the analysis of physiological samples. A scanning monochromatic spectrophotometer may be used to determine the absorbance of the sample under control of a central processing unit. Outputs from one of several ion selective electrodes may also be selected by the system. The information obtained from the measurements is stored in memory or ouputted to output devices. Information about the test parameters may be read from an optical bar code associated with the test kit for the particular chemical analysis.
Abstract:
An apparatus for measuring amylose and/or amylopectin content in rice. A near infrared light beam having its wavelength in a range of from about 1900 nm to about 2500 nm is applied to sample rice (5). A detector (26, 27,28) receives light reflected from and/or transmitted through the sample rice (5), to generate signals representative of luminous intensity of the received light. A memory device (122) has stored therein content conversion coefficients set for the amylose and/or amylopectin. A calculation device (123) calculates the amylose and/or amylopectin content in the sample rice (5), based on the detecting signals from the detector (26,27,28) and the content conversion coefficients stored in the memory device (122). The calculated content is displayed by a display device (126,127).
Abstract:
Instrumentation to detect the presence of, or to measure the concentration of, a gas or pollutant in a gaseous environment. With the use of gas filter correlation techniques and energy beams having suitable wavelengths, the presence and concentrations of these can be detected and measured, not only in flowing streams such as in exhaust stacks, but above a ground area and around its perimeter. A calibration means using a retrodirective reflector is also shown.
Abstract:
A beam of light falling within the range of 180 to 3,000 nanometers is transmitted through a flow cell in an optical compartment of an absorbance detector after warm up of the equipment while the eluant flows through the flow cell from a chromatographic column. The column extends upwardly from the absorbance detector into an air chamber having a volume of approximately 0.25 cubic foot formed with acrylic walls. Air flows from the absorbance detector under the power of a fan at approximately 10 cubic feet per minute upwardly through an air duct having a cross section of approximately 1.5 square inches to the top where it connects with the air chamber, the speed of the motor being adjustable until temperature varies less than one degree Celsius between the flow cell and the lower 10 centimeters of the column. Under these conditions Schlieren noise from the flow cell due to flow-induced thermo-optical effects is reduced.