In Tech | Exhaust Gas Temperature Sensor Types and What Need to Know
Exhaust Gas Temperature Sensor Types and What Need to Know
Post by Allen Huang, Updated on May 21st, 2021
About Exhaust Gas Temperature Sensor, known as EGTS, is a monitoring sensor that measures the temperature of exhaust gas. Generally found in diesel engine vehicle within its exhaust system, it has also been used for petrol vehicle to monitor high temperature area. EGT mainly function as thermometer that continuously feedback signal in voltage to engine control unit (ECU) to monitor overall condition. For starters, overheating can be a major damage to vehicle’s components, and with EGT sensors integrated under the hood, ECU is able to make corresponding action instantly such as reduce power to cool down or alerting driver that dedicated component is in low efficiency. EGT sensors are implanted across exhaust aftertreatment system to oversight its process and effectively reduce harmful gas for emission regulation and most importantly - The great nature.
What are the types of EGT sensor and the difference?
Generally, there are two technologies of EGT sensor, PTC technology and NTC technology. In term of internal specification, there are various characteristic that fit for different location and temperature range requirement.
PTC Exhaust Gas Temperature Sensor
PTC stands for “Positive Temperature Coefficient”, it means the resistance elevate while temperature increase. PTC temperature sensors’ resistance variation is in linear scale, and temperature detection range is from -70°C to 900°C. PTC EGT sensor integrates PT200 sensing element constructed via thin film process. Its characteristic indicates 200Ω (Ohm) when temperature is at 0°C and it can precisely detect temperature difference.
NTC Exhaust Gas Temperature Sensor
NTC stands for “Negative Temperature Coefficient”, it means the resistance descent while temperature increase. NTC temperature sensors’ resistance variation is in logarithmic (log) scale, and temperature detection range is from -40°C to 900°C depends on thermistor type. NTC EGT sensor is constructed via press forming process with embedded conductor and made in various specification that require different particular temperature sensitivity sensing range. it’s especially sensitive to temperature variation.
Where Exhaust Gas Temperature Sensor (EGTS) Locate and What it Does?
Exhaust gas temperature sensor (EGTS) locate at various position around exhaust aftertreatment system. Every EGT sensor have their dedicated protecting components and monitoring factors.
Before and After Turbocharger (Turbo)
EGT sensor around Turbocharger is to check the component’s temperature have descent to around 150°C to 200°C for proper function. Meanwhile, monitoring the component’s temperature in case of overheating.
Before and After Diesel Oxidation Catalyst (DOC)
EGT sensor around diesel oxidation catalyst is to monitor the entry exhaust temperature with minimum temperature of 200°C in order to start operational. Meanwhile, monitoring the component’s health, such as clogged DOC and in case of overheating.
Before and After Diesel Particulate Filter (DPF)
EGT sensor around diesel particulate filter (DPF) is to check DPF regeneration process is complete and effective. Meanwhile, monitoring the component’s health, such as clogged DPF and in case of overheating.
Before and After Selective Catalytic reduction (SCR)
EGT sensor around selective catalytic reduction (SCR) is to monitor the entry exhaust temperature that required certain temperature around 200°C to 400°C in order to start operational and the exit exhaust has been proper dealt with.
Conclusion
In conclusion, Exhaust gas temperature sensor plays an important role within vehicles’ exhaust system. Without proper maintenance, it can lead to reduce power during driving and even damage vehicle’s component that is unrepairable due to overheating. Overall, the diesel exhaust gas is very toxic to human health. Therefore, exhaust aftertreatment system was integrate within the vehicle and emission standard is regulated to better of our living environments.
Ceradex offers both PT200 EGT sensor and NTC EGT sensor across overall Exhaust Gas Temperature sensor range. Feel free to contact us for your EGT sensor solution!!
