carbon monoxide detector 400 ppm image
Chua
please help me...
i need it for my report..
.
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.i need the gadgets whoch are really rare...
Answer
CO (poison) detectors - should be in every house in case furnace has issues
Sensors
Early designs were basically a white pad which would fade to a brownish or blackish colour if carbon monoxide were present. Such chemical detectors are cheap and widely available, but only give a visual warning of a problem. As carbon monoxide related deaths increased during the 1990s, audible alarms became standard.
The alarm points on carbon monoxide detectors are not a simple alarm level (as in smoke detectors) but are a concentration-time function. At lower concentrations (eg 100 parts per million) the detector will not sound an alarm for many tens of minutes. At 400 parts per million (PPM), the alarm will sound within a few minutes. This concentration-time function is intended to mimic the uptake of carbon monoxide in the body while also preventing false alarms due to relatively common sources of carbon monoxide such as cigarette smoke.
There are four types of sensors available and they vary in cost, accuracy and speed of response.[10] The latter three types include sensor elements that typically last up to 10 years. At least one CO detector is available which includes a battery and sensor in a replaceable module. Most CO detectors do not have replaceable sensors.
[edit]Opto-Chemical
The detector consists of a pad of a coloured chemical which changes colour upon reaction with carbon monoxide. They only provide a qualitative warning of the gas however. The main advantage of these detectors is that they are the lowest cost, but the downside is that they also offer the lowest level of protection.
[edit]Biomimetic
A biomimetic (chem-optical or gel cell) sensor works with a form of synthetic hemoglobin which darkens in the presence of CO, and lightens without it. This can either be seen directly or connected to a light sensor and alarm. Battery lifespan usually lasts 2-3 years. Device lasts on the average of about 10 years. These products were the first to enter the mass market but have now largely fallen out of favour.
[edit]Electrochemical
This is a type of fuel cell that instead of being designed to produce power, is designed to produce a current that is precisely related to the amount of the target gas (in this case carbon monoxide) in the atmosphere. Measurement of the current gives a measure of the concentration of carbon monoxide in the atmosphere. Essentially the electrochemical cell consists of a container, 2 electrodes, connection wires and an electrolyte - typically sulfuric acid. Carbon monoxide is oxidized at one electrode to carbon dioxide while oxygen is consumed at the other electrode. For carbon monoxide detection, the electrochemical cell has advantages over other technologies in that it has a highly accurate and linear output to carbon monoxide concentration, requires minimal power as it is operated at room temperature, and has a long lifetime (typically commercial available cells now have lifetimes of 5 years or greater). Until recently, the cost of these cells and concerns about their long term reliability had limited uptake of this technology in the marketplace, although these concerns are now largely overcome. This technology is now the dominant technology in USA and Europe.
[edit]Semiconductor
Thin wires of the semiconductor tin dioxide on an insulating ceramic base provide a sensor monitored by an integrated circuit. This sensing element needs to be heated to approximately 400 deg C in order to operate. Oxygen increases resistance of the tin dioxide, but carbon monoxide reduces resistance therefore by measurement of the resistance of the sensing element means a monitor can be made to trigger an alarm. The power demands of this sensor means that these devices can only be mains powered although a pulsed sensor is now available that has a limited lifetime (months) as a battery powered detector. Device usually lasts on the average of 5-10 years. This technology has traditionally found high utility in Japan and the far east with some market penetration in USA. However the superior performance of electrochemical cell technology is beginning to displace this technology
CO (poison) detectors - should be in every house in case furnace has issues
Sensors
Early designs were basically a white pad which would fade to a brownish or blackish colour if carbon monoxide were present. Such chemical detectors are cheap and widely available, but only give a visual warning of a problem. As carbon monoxide related deaths increased during the 1990s, audible alarms became standard.
The alarm points on carbon monoxide detectors are not a simple alarm level (as in smoke detectors) but are a concentration-time function. At lower concentrations (eg 100 parts per million) the detector will not sound an alarm for many tens of minutes. At 400 parts per million (PPM), the alarm will sound within a few minutes. This concentration-time function is intended to mimic the uptake of carbon monoxide in the body while also preventing false alarms due to relatively common sources of carbon monoxide such as cigarette smoke.
There are four types of sensors available and they vary in cost, accuracy and speed of response.[10] The latter three types include sensor elements that typically last up to 10 years. At least one CO detector is available which includes a battery and sensor in a replaceable module. Most CO detectors do not have replaceable sensors.
[edit]Opto-Chemical
The detector consists of a pad of a coloured chemical which changes colour upon reaction with carbon monoxide. They only provide a qualitative warning of the gas however. The main advantage of these detectors is that they are the lowest cost, but the downside is that they also offer the lowest level of protection.
[edit]Biomimetic
A biomimetic (chem-optical or gel cell) sensor works with a form of synthetic hemoglobin which darkens in the presence of CO, and lightens without it. This can either be seen directly or connected to a light sensor and alarm. Battery lifespan usually lasts 2-3 years. Device lasts on the average of about 10 years. These products were the first to enter the mass market but have now largely fallen out of favour.
[edit]Electrochemical
This is a type of fuel cell that instead of being designed to produce power, is designed to produce a current that is precisely related to the amount of the target gas (in this case carbon monoxide) in the atmosphere. Measurement of the current gives a measure of the concentration of carbon monoxide in the atmosphere. Essentially the electrochemical cell consists of a container, 2 electrodes, connection wires and an electrolyte - typically sulfuric acid. Carbon monoxide is oxidized at one electrode to carbon dioxide while oxygen is consumed at the other electrode. For carbon monoxide detection, the electrochemical cell has advantages over other technologies in that it has a highly accurate and linear output to carbon monoxide concentration, requires minimal power as it is operated at room temperature, and has a long lifetime (typically commercial available cells now have lifetimes of 5 years or greater). Until recently, the cost of these cells and concerns about their long term reliability had limited uptake of this technology in the marketplace, although these concerns are now largely overcome. This technology is now the dominant technology in USA and Europe.
[edit]Semiconductor
Thin wires of the semiconductor tin dioxide on an insulating ceramic base provide a sensor monitored by an integrated circuit. This sensing element needs to be heated to approximately 400 deg C in order to operate. Oxygen increases resistance of the tin dioxide, but carbon monoxide reduces resistance therefore by measurement of the resistance of the sensing element means a monitor can be made to trigger an alarm. The power demands of this sensor means that these devices can only be mains powered although a pulsed sensor is now available that has a limited lifetime (months) as a battery powered detector. Device usually lasts on the average of 5-10 years. This technology has traditionally found high utility in Japan and the far east with some market penetration in USA. However the superior performance of electrochemical cell technology is beginning to displace this technology
Chemistry conversion question?
Angela L
Carbon Monoxide (CO) detectors sound an alarm when peak levels of carbon monoxide reach 100 parts per million(ppm). This level roughly corresponds to a composition of air that contains 400,000 micro grams carbon monoxide per cubic meter of air. Assuming the dimensions of a room at 18ft x 12ft x 8ft, estimate the mass of carbon monoxide in the room that would register 100ppm on a carbon monoxide detector.
help me please :)
Answer
convert ft to meters then multiply to get m3 then x 400,000micrograms
http://www.kentchemistry.com/links/Measurements/dimensionalanalysis.htm
convert ft to meters then multiply to get m3 then x 400,000micrograms
http://www.kentchemistry.com/links/Measurements/dimensionalanalysis.htm
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