Infrared carbon dioxide sensors

The GD-888 SERIES of portable and wall-mounted. Infrared Carbon Dioxide Gas analyzers are available from as low as 0-9990 ppm up to 0-100.0% full scale. Bectrochemical oxygen and toxic gas sensors can also be added inline with the built-in air pump. Most units come with backlit LCD display, adjustable alarm, 0-1 VDC output, and rechargeable batteries that allow for portable use or continuously on AC power with the battery charger. 

The deterrnination of impurities in the hehum-group gases is also accompHshed by physical analytical methods and by conventional techniques for measuring the impurity in question (93), eg, galvanic sensors for oxygen, nondispersive infrared analysis for carbon dioxide, and electrolytic hygrometers for water. 

Mounting electrodes in a bioreactor is costly, and there is an additional contamination risk for sensitive cell cultures. Some other sensors of prac ticai importance are those for dissolved oxygen and for dissolved carbon dioxide. The analysis of gas exiting from a bioreactor with an infrared unit that detects carbon dioxide or a paramagnetic unit that detects oxygen (after carbon dioxide removal) has been replaced by mass spec trophotometry. Gas chromatographic procedures coupled with a mass spectrophotometer will detect 1 the volatile components. 

Carbon monoxide and carbon dioxide can be measured using the FTIR techniques (Fourier transform infrared techniques see the later section on the Fourier transform infrared analyzer). Electrochemical cells have also been used to measure CO, and miniaturized optical sensors are available for CO 2 monitoring. 

Bingham, G.E., Gillespie, C.H., McQuaid, J.H., Lawrence Livermore National Laboratory, and Dooley, D.F., Molectron Corp., A miniature, battery-powered, pyroelectric detector-based differential infrared absorption sensor for ambient concentrations of carbon dioxide, Ferroelectrics, 34, 15-19,... 

In a few cases, small optical infrared absorption monitors have been integrated into electronic nose sensors [11], mostly for detection of the carbon dioxide evolution from cells. The 3000-4000 nm filters are normally used. 

Long-term (>1000 h) tests were performed in a separate reactor equipped with a sohd-state on-line hydrogen sensor and infrared carbon monoxide and carbon dioxide detectors. Batch sampling was performed at the exit stream. This system allowed us to determine the durabihty of the autothermal reforming catalyst and to determine if there are any long-term problems (poisoning, coking) caused by the fuel components. 

Carbon dioxide can be assayed via infrared absorption, or electrochemically by measuring the changes in the pH of a buffer solution as a result of varying CO2 partial pressure above the solution. The latter principle can also be applied to optical sensors. 

Growth of biomass is typically of crucial importance in SSF processes, even if the biomass itself is not the final product. The processes of nutrient consumption, oxygen consumption, carbon dioxide evolution, waste heat release, and product formation are intimately related to the growth process and therefore it is usually essential to characterize the growth curve. Unfortunately, on-line biomass measurement is still impossible in SSF, despite efforts to develop on-line sensors based on Fourier transform infrared spectroscopy [176]. 

Worhoff K, Lambeck PV, Driessen A (1999) Design, tolerance analysis, and fabrication of silicon oxynitride based planar optical waveguides for communication devices. J Lightwave Technol 17 1401-1407 Wu B, Chang C, Sree U, Chiu K (2006) Measurement of non-methane hydrocarbons in Taipei City rmd their impact on ozone formation in relation to air quality. J Anal Chim Acta 576 91-99 Zhang G, WuX (2004) A novel CO gas analyzer based on IR absorption. Opt Lasers Eng 42 219-231 Zhang G, Ltri J, Ytran M (2000) Novel carbon dioxide gas sensor based on infrared absorption. Opt Eng 39 2235-2240... 

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