5 COMPONENTS Description of components XF 95 series 2.3 TEMPERATURE SENSORS The vehicle has a number of temperature sensors, such as: - coolant temperature sensor - inlet air temperature sensor - fuel temperature sensor - ambient air temperature sensor 2 These sensors are temperature-sensitive resistors. The resistance of these sensors changes considerably with rises or drops in temperature. There are two types of temperature sensor: - NTC resistor (Negative Temperature Coefficient). - PTC resistor (Positive Temperature Coefficient). NTC resistor In an NTC resistor, the resistance value reduces when the temperature rises. Application: - measuring coolant temperature.
W 5 01 010 PTC resistor In a PTC resistor, the resistance value increases when the temperature rises. In the PTC resistor, in contrast to the NTC resistor, there will be a great change in resistance within a small temperature range. Application: - measuring air temperature when cab heater is on W 5 01 011 2-4 200303