Temperature sensors use resistors whose resistance changes with temperature. Two different types of sensors are common: PTC and NTC. While with PTC (Positive Temperature Coefficient) resistance increases with rising temperature, with NTC (Negative Temperature Coefficient) resistance decreases with rising temperature. All NTK sensors are NTC types. NTC sensors are more accurate in measuring than PTC sensors; but as NTC sensors used to be sensitive on high temperatures, mostly PTC were used to measure exhaust gas temperature. NTK EGT Sensors use temperature resistant elements that cover a range from -40°C up to +900°C. When it comes to the installation position of EGT Sensors, the sensor specialist supplies products such as vehicle-specific sensors that:
- measure the exhaust gas temperature before and after the turbocharger
- measure the exhaust gas temperature before and after the diesel oxidation catalytic converter
- are fitted before/after the diesel particulate filter and/or the 3-way catalytic converter
EGT Sensors serve as a temperature monitor for turbochargers, catalytic converters, diesel particle filters, and nitrogen oxide reduction systems. They are used to monitor the optimum operating point, to protect the relevant components from temperature overload, and to keep them in the desired temperature range for optimal conversion rates, thus making them an important component for the reduction of harmful emissions from vehicles.