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Ammonia Sensor – Know The Different Options AvailableAn ammonia sensor can help detect the presence of ammonia gas, but these devices do have their limitations.
Ammonia is one of the most widely produced chemicals in the civilized world. It is used in agriculture, in fertilizers, and may also be used as a refrigerant . Ammonia is also used in the pulp and paper industry as well as the oil and petrochemical industries. Ammonia is a highly toxic and corrosive substance that can kill people when it is present in large quantities. Anhydrous ammonia, which is the liquid form of ammonia, will expand 850 times when exposed to air, quickly forming deadly clouds of vapor. That is why an ammonia sensor is such a vital piece of safety equipment in areas where large amounts of ammonia are present. There are four different kinds of ammonia sensor that are commonly used. Each one has its advantages as well as its limitations. For best results the sensor should be suited to the environment being monitored. The four sensors are infrared, chemosorption electrochemical and charge carrier injection. Infrared Infrared sensors measure ammonia gas by calculating how much infrared light is absorbed in a special chamber. This method can be used to create a sort of ‘fingerprint’ of known contaminants, including ammonia gas, making it possible to test for its presence as well as measure how much is present. Advantages of this type of sensor include the precision in which it detects ammonia and its stability. It is not harmed by ammonia in high concentrations but it is potentially vulnerable to fluctuations in temperature and humidity. It is also considerably more expensive than other detectors. Chemisorption A chemisorption sensor measures the level of electrical conductivity in the air to determine if gases are present. When air is clean, electrical conductivity will be low, but when gas oxidizes on the sensor, conductivity increases. This type of sensor is typically used when it is necessary to detect the presence of gases such as carbon monoxide, hydrogen, ammonia and other gases. The main benefit of a chemisorption sensor is its ability to determine if any type of potentially dangerous gas is present. However, it doesn’t single out ammonia, so readings can be unclear. It is a lower cost, long-lasting unit. Electrochemical Different electrochemical sensors can be obtained to detect specific substances. This type of sensor measures the electrochemical change that occurs in a special electrolyte gel substance when a certain gas, such as ammonia, is present. These devices are ideal when the presence of only one specific gas needs to be monitored. They use minimal power and are relatively inexpensive. Charge carrier injection A charge carrier injection sensor is different from other sensors. It detects ammonia using ‘charge carrier’ molecules, which are injected into a sensor element, causing a variation in the amount of resistance. This type of ammonia sensor is ideal for use in freezers and other extremely cold environments. It can also be used in environments that are devoid of oxygen. To read about other related subjects, please follow these links:
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