Resistivity is how easily electricity flows through something. So, something like copper, which is used a lot in wiring, would be less resistant than rubber, which is used to stop electric currents. Copper carries electricity while rubber stops the current because of differences in conductivity. An MOS sensor has a metal strip or film that is exposed to the air you want to test. This strip has a constant electric current running through it. As the target gas comes into contact with the piece, it will interact with the metal and change the chemical composition either through a reduction or oxidation reaction.
When this happens, the resistivity, or conductivity, or the metal will be altered. The kind of resistance change, whether increasing or decreasing, and the magnitude of this change determines the concentration of the target gas. Based on what kind of metal it is, different gases will react to the strip.
While MOS sensors do very well in CO2 levels above ppm, this level is already high enough to affect you. NDIR sensors are the longest-lasting monitor currently on the market. While both electrochemical and metal oxide semiconductor sensors have made considerable strides in this department, they are still behind the NDIR sensor type, which usually lasts years or more.
Both MOS and electrochemical sensors can have something called cross-sensitivity bias. When a substance other than CO2 reacts in the sensor, it changes the electrical properties of the sensor and the readings it gives you. While the other kinds of sensors have their uses, NDIR sensors are the best choice for portable, accurate carbon dioxide monitoring.
And don't forget, you can always read more about everything you need to know about CO2 and how it affects our health and our planet here. Kaiterra is a global company on a mission to end air pollution. We make air monitors that empower people to make small changes in their everyday lives and help with researchers, NGOs, and governments around the world to end air pollution at the source. Meet the Laser Egg Series Know more about your air and breathe better with the world's most popular air quality monitor.
Carbon monoxide blocks the ability of your blood to carry oxygen, replacing the spot that oxygen takes on the hemoglobin in your red blood cells. This iron-rich compound is how your blood carries oxygen around the body, and carbon monoxide bonds to hemoglobin much tighter than oxygen alone. Over time, as more and more hemoglobin is blocked from doing its job by carbon monoxide, your blood just can't carry enough oxygen to keep your tissues going, especially the brain.
They begin to fail, causing headaches, nausea, unconsciousness, and eventually, death. There are several different ways to detect carbon monoxide, but most home carbon monoxide detectors use an electrochemical sensor.
These rely on how the behavior of a chemical changes when carbon monoxide is around. Inside the carbon monoxide alarm is a small sensor with three electrodes on it.
These three electrodes lead into a container of a chemical called the electrolyte. This container is gas permeable, meaning that gas from the atmosphere can pass freely into and out of it. A small voltage is applied between two of the electrodes called the working and the reference electrodes. When carbon monoxide enters the sensor, it reacts with the oxygen also present in the atmosphere, releasing an electron and creating a small current between the electrodes.
Some sensors use electrodes coated with platinum or other metals that catalyze the reaction of carbon monoxide and oxygen, helping it to happen quicker than it would normally. This small current is what a carbon monoxide detector is looking for.
It uses this to measure the amount of carbon monoxide: the more of it there is in the air, the more current the sensor generates. Some sensors show you the carbon monoxide level on a display: a useful feature that helps to reassure that the sensor is working. Contact a professional to service any fuel-burning appliances in your home. If anyone is showing flulike symptoms, call or your local emergency services number and leave the building immediately.
Most nonfatal exposures happen in people's homes, which is why it's important to have a CO detector to go along with — or as part of — your smoke detector. Before selecting a carbon monoxide CO detector, do a little research.
Determine whether your local laws require you to have CO detectors of a particular type or configuration. You'll need to decide whether you'd rather have a battery -operated or plug-in detector. A plug-in unit goes into any wall outlet and can be moved to another room if necessary.
This may not seem like a big deal in the case of temporary outages, but imagine a long power outage during winter. You may turn to a portable space heater or a wood stove to keep your home warm — exactly the sort of fuel-burner that may release CO into the air. Battery-operated units, on the other hand, are typically attached permanently to a surface in your home. This usually isn't a problem unless your detector mistakes other gases for CO, causing false alarms and prompting you to move the unit.
Depending on the size of your home and the number and location of fuel-burning appliances, a combination of types may work best. Follow the manufacturer's instructions for placement, maintenance and scheduled inspection. The NFPA also recommends using detectors that can be linked so that one alarm sets off all the others, alerting the whole household. Installing CO detectors is only one step in preventing carbon monoxide poisoning. Other important steps include:. Finally, test your carbon monoxide detector monthly — it's your last line of defense against a malfunctioning stove or heater.
Sign up for our Newsletter! Mobile Newsletter banner close. Mobile Newsletter chat close. Mobile Newsletter chat dots. Mobile Newsletter chat avatar. Mobile Newsletter chat subscribe. Home Improvement. Home DIY. Household Safety. How Carbon Monoxide Detectors Work. The exact components can vary from one model to another, but here's a run-down of the basic parts: " ". The interior of a carbon monoxide detector.
When pressed, the peak button causes the LCD screen to display the highest level of CO recorded since the last reset. A small silicon microchip sends an electronic charge, a sort of "what to do" signal, to the other parts of the detector. The chip is fused to a copper-wired, integrated electronic circuit panel, which is the base for the unit. Light-emitting diodes LEDs use lights to let you know how the unit is functioning and whether the battery needs to be replaced.
Wires to the building's electrical system or a battery provide power to the unit.
0コメント