October 2, 2006
Workers once relied on canaries, mice and rats to warn them of toxic gas in the atmosphere. Inefficient and ineffective methods of gas detection are now a thing of the past.
Now workers rely on microprocessors and gas sensors to consistently monitor and react to the dangerous threat of toxic and combustible vapors, as well as ambient oxygen changes.
Following a similar technology explosion as the cell phone industry, portable gas detectors that once weighed a few pounds are now measured in ounces, and the high price that customers once had to pay is now measured in hundreds of dollars instead of thousands. Letâ€™s look at some trends occurring in the world of portable gas detection instrumentation.
Getting smallerGas sensor manufacturers have been busy reducing the size of the sensors that fit in portable gas detectors, and the difference is dramatic. Sensors operate on the same detection principles and contain the same internal components as previous sensors, but improvements in plastic design have allowed these new sensors to be decreased by up to 75 percent in size and 95 percent in weight.
Miniaturization and minimization of electronic components has also helped decrease the overall size of the detector. Todayâ€™s electronic components complete more functions at a higher rate of speed while decreasing to one-third of their previous size. The reduction of electronic components should not be looked at as lowering quality. Gas detection manufacturers understand that their products save lives and they cannot afford to produce products that offer any less than the highest level of quality.
Improvements in the plastics industry have enabled the housing of the gas detector to become smaller, as it now wraps itself around the electronic package like a durable layer of skin. Electronic parts are now molded directly into the plastic, which decreases the amount of space used in the design.
Due to these advancements, the average portable multi-gas detector now weighs approximately six to seven ounces and is roughly the size of a cellular telephone. The biggest benefit of this reduction is that workers can easily do their jobs without having to deal with a bulky, cumbersome detector.
Lower cost of ownershipIn the past, many companies were aware that their personnel should be protected but they could not afford a gas detector for every employee. Today, with inexpensive gas detectors, every person on site should be and can be protected.
Overall cost of ownership has also decreased significantly. As sensor technology has matured, the regularly scheduled calibration of a gas detector has been extended. The need to calibrate weekly or monthly has been eliminated.
Calibration and bump test stations have become a common accessory. Their sole purpose is to automate the bump or calibration tests and to reduce the personnel cost and gas usage cost associated with the maintenance of gas detection.
Better sensorsPhotoionization and infrared technology, which use frequencies of light to detect gas, are no longer used in labs, but are now scaled down and portable.
North American industry has defined the four most common gases (oxygen, carbon monoxide, hydrogen sulphide and combustible) that can be encountered in a confined space, but there are many other gases that are just as dangerous and their toxic effects are now becoming more known to the industry.
Carbon dioxide can be found in many confined spaces, breweries, wineries and is becoming widely used in the oil industry to help extract oil from mature fields. Until recently there was no affordable method that could reliably detect it. Carbon dioxide is known to be one of the most common confined space gases, which has led Austria and Germany to make it part of their confined space regulations.
Other dangerous vapors known as volatile organic compounds (VOCs) make up many of the dangerous gases that workers can encounter. Some of these common VOCs are industrial cleaners, fuels and pesticides that are found in confined spaces every day. Combustible sensors were once believed to be sufficient to detect these compounds. Unfortunately the combustible sensor is not sensitive enough at low levels to detect the toxicity of these vapors. A photoionization sensor, or PID, in this situation is superior, as it can measure at a low enough level to protect workers from the toxic effects of these compounds. In cases where a combustible sensor can become damaged by compounds in the air, like silicone or lead, the PID sensor will be unaffected.
A few years ago a portable PID or infrared CO2 detector could cost up to $3,000 or $4,000. With advancements in technology, costs have come down and these gas detectors can now be purchased for less than $2,000.