Portable oxygen analyzers

All safety equipment and systems should be scheduled for regular inspection and test. Nitrogen blanketing systems should be inspected at least weekly. It is not sufficient to check that the nitrogen is open to the tank. The atmosphere in the tank should be tested with a portable oxygen analyzer to make sure that the oxygen concentration is below 5%. 

The atmosphere inside every stack should be monitored regularly, say daily, for oxygen content. Large stacks should be fitted with oxygen analyzers that alarm at 5% (2% if hydrogen is present). Small stacks should be checked with a portable analyzer. 

Commercial test rack with the following components from top to bottom CO meter, oxygen meter, NOx meter, total hydrocarbons (THC) meter, and gas conditioning system. Smaller, less accurate, portable combustion analyzers are also available. These analyzers are generally equipped with solid state sensors to measure commonly encountered combustion gases. 

Oxygen sensing probes, oxygen analyzers, water vapor analyzers, portable O2/CO2 analyzers, oxygen sensor... 

There is a variety of portable devices that give direct readings of certain gases or vapors, such as oxygen meters, combustible gas meters that indicate the presence of particular flammable gases, and portable infrared analyzers, and gas chromatographs for assessing many different materials. 

Even if the device has been properly calibrated for the particular gas in air, some analyzers such as catalytic bead types will not function in oxygen deficient atmospheres containing less than about 10 vol% oxygen. Some portable analyzers are supplied with antistatic tubing but others are supplied with nonconductive tubing such as Tygon. 

On all centrifuges that handle flammable solvent, the oxygen content should be continuously monitored. At the very least, it should be checked every shift with a portable analyzer. In addition, the flow of nitrogen should be adequate, clearly visible, and read regularly. 

Fig. 9a. Portable combustion gas analyzer uses fuel cell technology to measure oxygen, carbon monoxide and carbon dioxide with 0.2% accuracy for 02 and C02, and 1% for CO.

Miller and co-workers show an on-stream sampler and a portable GC system to analyze stack gases as part of the requirements of determination of particulate matter from incinerator stacks. The concentrations of carbon dioxide, oxygen, and carbon monoxide are measured and that of nitrogen is calculated by difference. This method is of higher precision and can save time and labor when compared with the Orsat analyzer method. Further, this GC system is portable and all the components are mounted on a 2 ft by 3 ft laboratory cart, which makes mobile measurements possible. A summary of some of the techniques used is presented in Table 6.2. 

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. 

In general, on-stream analyzers are not as reliable as lab analysis and should not be used. However, for measuring the oxygen content of furnace flue gas or the H2S and SO2 content of sulfur-bearing gas streams, portable analyzers are best. These portable instruments need to be obtained and calibrated in advance. 

The advent of easy access to the satellite-based global positioning system (GPS) and availability of off-the-shelf portable probes and rapid analyzers for a number of water quality determinants have enabled the development of systems that can be carried on small survey vessels to map water quality conditions. Rapid data acquisition is now practical using probes and sondes for measuring temperature, conductivity, turbidity, pH, and dissolved oxygen fluorometric technologies for chlorophyll biomass and phytoplankton composition flow injection and loop flow analysis for some nutrient species and acoustic Doppler-based devices for current profiling. 

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