Thursday, February 26, 2009

Deep-Sea Gas Analyzers

The Deep-Sea Gas Analyzer provides an accurate measurement of a variety of gases at depths of up to 2500 meters. The instrument employs a membrane gas extractor and is capable of measuring virtually any gas in LGR’s catalog, including CH4, CO2, and various stable isotopomers. Self-sustained, remote operation is possible using the internal battery, gas handling system, and data storage. Possible applications include carbon sequestration in ocean waters, methane-hydrate studies, and hydrothermal-vent effluent analysis.
As described in the Theory Section (on www.lgrinc.com), the measurement strategy is based on high-resolution direct-absorption spectroscopy. As a result, the instrument is self-calibrating and provides an absolute, accurate gas concentration without reference standards. An internal computer can store data practically indefinitely for applications requiring unattended long-term standalone operation. These analyzers can also send real-time data to a data logger through analog, digital (RS232), and Ethernet outputs.

CO2 Isotope Analyzer

The CO2 Isotope Analyzer is an autonomous instrument capable of measuring the 13C/12C ratio in ambient carbon dioxide with better than 0.25‰ repeatability (for an integration time of 60 seconds) and without the need for costly consumables. This is possible because the instrument itself is built around conventional telecommunications-grade diode lasers that operate in the near-infrared spectral region. In addition, since the measurement strategy is based on high-resolution direct-absorption spectroscopy (see www.LGRinc.com, Theory Section), the instrument is not affected by other atmospheric gases or by changes in ambient atmospheric pressure. Thus the need for regular calibration with expensive reference gases is also significantly reduced compared with traditional analytical instruments.
The instrument includes an internal computer that can store data practically indefinitely on its hard drive (for applications requiring unattended long-term standalone operation), and send real-time data to a data logger through its analog, digital (RS232), and Ethernet outputs.

Singlet-Oxygen Analyzer

* High absolute accuracy
* Unsurpassed sensitivity
* Easy to use

The Quantitative Singlet-Oxygen Analyzer is designed to be readily interfaced into a variety of singlet-oxygen applications including optimization of singlet-oxygen generators, chemical oxygen-iodine laser studies, fundamental physical sciences, and plasma decontamination. Because the Analyzer is not affected by most common background gases, it provides a direct measure of singlet-oxygen density, [O2(a1∆g)], in a wide variety of these background gases with high precision (better than 1014 molecules/cm3) and a rapid response rate (data rate up to 10 Hz).
As described in the Theory Section (on www.LGRinc.com), the measurement strategy is based on high-resolution direct-absorption spectroscopy. As a result, the instrument is self-calibrating and provides absolute, accurate measurements of singlet-oxygen density. The instrument itself can be implemented for extractive sampling, or be customized by LGR to provide in-situ measurements of O2(a1∆g) under a variety of conditions (e.g. COIL test stands, plasma effluents).
For more information about Custom Instruments and Contract R&D and for papers about Singlet-O2 Analysis, go to www.lgrinc.com.

CO and N2O Analyzers

* Fast measurement rate (up to 20 Hz)
* Unsurpassed accuracy and precision
* Reliable (tested on-board several NASA aircraft)
* Measurements of N2O and CO in single instrument possible

Designed for many demanding applications including eddy-correlation flux measurements, chamber flux measurements, combustion diagnostics, and trace-gas monitoring, these Analyzers have been applied successfully on-board NASA DC-8 aircraft for trace-gas measurements in the upper troposphere / lower stratosphere. In fact, the High-Sensitivity CO Analyzer and the High-Sensitivity N2O Analyzer are ideal for measuring carbon monoxide and nitrous oxide, respectively, in ambient air with data rates of up to 10 Hz, less than 1% uncertainty (without calibration; much higher accuracy may be obtained with calibration), and better than 0.1% repeatability. Neither analyzer is affected by other atmospheric gases or changes in ambient atmospheric pressure.

Thursday, January 15, 2009

Paramagnetic Oxygen Analyzer

Within this category, the magnetodynamic or `dumbbell' type of design is the predominate sensor type. Oxygen has a relatively high magnetic susceptibility as compared to other gases such as nitrogen, helium, argon, etc. and displays a paramagnetic behavior. The paramagnetic oxygen sensor consists of a cylindrical shaped container inside of which is placed a small glass dumbbell. The dumbbell is filled with an inert gas such as nitrogen and suspended on a taut platinum wire within a non-uniform magnetic field. The dumbbell is designed to move freely as it is suspended from the wire. When a sample gas containing oxygen is processed through the sensor, the oxygen molecules are attracted to the stronger of the two magnetic fields. This causes a displacement of the dumbbell which results in the dumbbell rotating. A precision optical system consisting of a light source, photodiode, and amplifier circuit is used to measure the degree of rotation of the dumbbell. In some paramagnetic oxygen sensor designs, an opposing current is applied to restore the dumbbell to its normal position. The current required to maintain the dumbbell in it normal state is directly proportional to the partial pressure of oxygen and is represented electronically in percent oxygen. There are design variations associated with the various manufacturers of magnetodynamic paramagnetic oxygen analyzer types. Also, other types of sensors have been developed that use the susceptibility of oxygen to a magnetic field which include the thermomagnetic or `magnetic wind' type and the magnetopneumatic sensor. In general, paramagnetic oxygen sensors offer very good response time characteristics and use no consumable parts, making sensor life, under normal conditions, quite good. It also offers excellent precision over a range of 1% to 100% oxygen. The magnetodynamic sensor is quite delicate and is sensitive to vibration and/or position. Due to the loss in measurement sensitivity, in general, the paramagnetic oxygen sensor is not recommended for trace oxygen measurements. Other gases that exhibit a magnetic susceptibility can produce sizeable measurement errors. Manufacturers of the paramagnetic oxygen analyzer should provide details on these interfering gases.

Brimrose NIR Analyzer

A new series of miniature near-infrared (NIR) spectrometers is said to offer a cost-effective tool for inspecting incoming raw materials and product quality control. Compact, battery-powered Model 5030 ATOF-NIR Portable Analyzer from Brimrose Corp. of America, Baltimore, allows laboratory tests to be performed anywhere in a plant environment. The instrument, which sells for $28,000 (compared with $40,000 for larger units), is reportedly insensitive to ambient light, vibration, dust, and dirt. Its design allows for quick switchover from solids to liquids, and results appear instantly on its LCD. Applications include material identification or measurement of moisture content and active-ingredient levels. Once the instrument is calibrated, it reportedly can be used by an inexperienced operator.

Site ContentAnalyzer - CleverStat



CleverStat is a nifty tool I've been using recently for web site content analysis. Unlike numerous online apps, CleverStat makes a copy of the site on your hard drive and analyzes the entire thing and not only individual pages.

Residual Gas Analyzer

A residual gas analyzer (RGA) is a small and usually rugged mass spectrometer, typically designed for process control and contamination monitoring in the semiconductor industry. Utilizing quadrupole technology, there exists two implementations, utilizing either an open ion source (OIS) or a closed ion source (CIS). RGAs may be found in high vacuum applications such as research chambers, surface science setups, accelerators, scanning microscopes, etc. RGAs are used in most cases to monitor the quality of the vacuum and easily detect minute traces of impurities in the low-pressure gas environment. These impurities can be measured down to 10 − 14 Torr levels, possessing sub-ppm detectability in the absence of background interferences.

RGAs would also be used as sensitive in-situ, helium leak detectors. With vacuum systems pumped down to lower than 10 - 5Torr—checking of the integrity of the vacuum seals and the quality of the vacuum—air leaks, virtual leaks and other contaminants at low levels may be detected before a process is initiated.

Gas Analyzer

The Thermal and Evolved Gas Analyzer (TEGA) is a scientific instrument aboard the Phoenix spacecraft. TEGA's design is based on experience gained from the failed Mars Polar Lander. Soil samples taken from the Martian surface by the robot arm are eventually delivered to the TEGA, where they are heated in an oven to about 1,000ÂșC. This heat causes the volatile compounds to be given off as gases which are sent to a mass spectrometer for analysis. This spectrometer is adjusted to measure particularly the isotope ratios for hydrogen, oxygen, carbon, nitrogen, and heavier gases. Detection values as low as 10 parts per billion. The Phoenix TEGA has 8 ovens, which are enough for 8 samples.

A residual gas analyzer (RGA) is a small and usually rugged mass spectrometer, typically designed for process control and contamination monitoring in the semiconductor industry. Utilizing quadrupole technology, there exists two implementations, utilizing either an open ion source (OIS) or a closed ion source (CIS). RGAs may be found in high vacuum applications such as research chambers, surface science setups, accelerators, scanning microscopes, etc. RGAs are used in most cases to monitor the quality of the vacuum and easily detect minute traces of impurities in the low-pressure gas environment. These impurities can be measured down to 10 − 14 Torr levels, possessing sub-ppm detectability in the absence of background interferences.

RGAs would also be used as sensitive in-situ, helium leak detectors. With vacuum systems pumped down to lower than 10 - 5Torr—checking of the integrity of the vacuum seals and the quality of the vacuum—air leaks, virtual leaks and other contaminants at low levels may be detected before a process is initiated.