Expensive Spectrometers Research Articles

Optical measurements of gas temperatures in atmospheric pressure RF cold plasmas

Rotational temperatures can be estimated directly from the ratios between peaks in the ultra violet (UV) band of OH molecular spectra. With a relatively poor spectral resolution of approximately 0.4 nm, ratios between two broad band peaks near 308 and 309 nm are identified to be sensitive to the gas temperatures in the range of 350∼1000 K. In cold radio frequency (RF) generated atmospheric plasmas, rotational temperatures of molecules are measured to be in a relatively low temperature range of 400∼700 K. These temperatures are confirmed to be in good agreement with gas temperatures measured by thermocouples. This simple emission spectroscopy can be used to monitor gas temperatures in cold atmospheric plasmas without any expensive spectrometer.

Methods for making prisms with submultiple or half angles: applications to the measurement of the angles of Pechan and Pellin-Broca prisms

A simple technique is devised for making prisms with submul- tiple or half angles. As an application of these prisms, methods are sug- gested to measure the angles of the Pechan and Pellin-Broca prisms without using expensive spectrometers, autocollimators, and angle gauges. © 2002 Society of Photo-Optical Instrumentation Engineers.

Method for measurement of the angles of a tetragonal or corner cube prism

A simple technique is devised to measure the angles of tetragonal prisms without using expensive spectrometers, or autocollimators and angle gauges.

Method for measurement of the angles of a 45-deg deflecting (half penta) prism

A simple technique is devised to measure the angles of 45-deg deflecting (half penta) prisms, without using the expensive spectrometers, autocollimators, and angle gauges. (C) 2000 Society of Photo-Optical instrumentation Engineers.

Simple Sampling Method and Routine Gas Chromatography-Mass Spectrometry Analysis in 13C Breath Tests

The 13C-labeled CO2 breath tests are convenient methods for various uses. They can be used to measure gastric emptying rate of solids (1), detect fat malabsorption (2), and evaluate pancreatic lipase activity (3), exocrine pancreatic insufficiency (4), glucose adsorption and utilization (5), liver function control (6), and lactase deficiency (7) with appropriate 13C isotope-labeled compounds. In recent years, the 13C-urea breath test has been used to detect Helicobacter pylori (8). With an appropriate analytical background and the facilities required for the detection or quantification of labeled CO2, the 13CO2 breath test could be widely applied for diagnostic purposes in the medical practice. Although several infrared or mass spectrometric methods (9) are available, the transport of large volumes of gaseous samples to analytical centers as well as storage before measurement involves great problems. Therefore, we have developed a simple method that allows storage of these samples in minimal liquid volume. By this technique, the liberation of isotope-labeled CO2-containing gas occurs immediately before measurements. Because most medical centers are not equipped with expensive and complex isotope-ratio mass spectrometers but generally have a routine low-mass-resolution gas chromatography-mass spectrometry (GC-MS) apparatus, we have also used a simple detection method for 13CO2 by standard GC-MS techniques. Analysis requires only a few minutes, and the method is suitable for selection of 13CO2-containing samples. In our test experiments, we used an air …

Method for measurement of the angles of a penta prism

A simple technique is devised to measure the angles of penta prisms, without using expensive spectrometers, autocollimators, and angle gauges. (C) 1998 society of Photo-Optical Instrumentation Engineers.

Method for measurement of the angles of an equilateral (60-deg) prism

A simple technique is devised io measure the angles of equilateral (60-deg) prisms, without using the expensive spectrometers, autocollimators, and angle gauges. The method can be extended to unpolished and opaque prisms made out of materials other than glass. (C) 1997 Society of Photo-Optical Instrumentation Engineers.

Method for measurement of the angles of 90-, 45-, 45-deg and 60-, 30-, 90-deg prisms

A simple technique is devised to measure the angles of 90-, 45-, 45-deg and 60-, 30-, 90-deg prisms without using expensive spectrometers, autocollimators, and angle gauges. The method can be extended to unpolished and opaque prisms made of materials other then glass. (C) 1997 Society of Photo-Optical instrumentation Engineers.

Optical Sensors based on Porous Silicon Multilayers: a Prototype

AbstractPorous silicon multilayers are easily produced by a variation of the current density during the electrochemical etching process. The obtained porosity profile in depth is equivalent to a refractive index profile. Preparing appropriate multilayer systems one can design optical filters with sharp reflectivity peaks from the infrared through the whole visible spectral range (dielectric mirrors). Stability in time is achieved applying a suitable oxidation process. In many cases of optical process and material control the required spectral decomposition of the probing light can be done with sufficient accuracy by a set of porous silicon optical filters whose spectral characteristics can lbe adapted easily to the given problem. In this work we present the prototype of an optical sensor that is a low-cost alternative to ‘real’ (and expensive) spectrometers. Application examples in the infrared and visible are given to demonstrate the sensor performance;.

Design considerations for a multiplexed spectrometer capable of simultaneous acquisition of multiple sample spectra

Abstract In order to make optimum use of expensive and vulnerable spectrometers in the industrial environment, it is desirable to obtain spectra from as many samples and/or spatially-separated sampling positions as possible using one spectrometer. This may be achieved by consecutive sampling; however, simultaneous sampling is possible if a suitable multiplexing scheme is devised. An outline design is presented for a multiplexed spectrometer capable of simultaneous acquisition of multiple sample spectra. Optical or electrical signals from an arbitrary number of individual samples are encoded by presenting them in various combinations to a single spectrometer or other signal detector. The switching of the signals may be dictated by the coefficients of the Hadamard S -matrix of the appropriate order; spectra of the individual samples may then be recovered by an inverse Hadamard transform. The method described, although general, is particularly suited to IR and Fourier transform Raman spectroscopy.