On an inner wall surface of a plug hole, an internal thread portion and a seat portion are formed. The seat portion has a tapered seat surface. A glow plug with a combustion pressure sensor includes a housing, a glow heater, a load transfer member, and a pressure detector. The housing has an external thread and a seat facing portion. The seat facing portion has a tapered contact surface in surface contact with the tapered seat surface. A recessed portion recessed to be in non-contact with the seat portion is formed annularly about a central axis of the housing.

A heater includes a ceramic body of bar shape; and a heat-generating resistor disposed in an inside of the ceramic body, when viewed in a transverse section, the heat-generating resistor including at least one step portion provided in an outer periphery part of the heat-generating resistor, the at least one step portion having such a shape that semicircular portions bisected in a diametrical direction of the heat-generating resistor deviate from each other along the diametrical direction.

A pressure-sensor-integrated glow plug which can increase reliability of a bonding portion between a ceramic heater and a metal-made outer sleeve while being manufactured with relatively simple manufacturing steps and, at the same time, can maintain airtightness over a long period, and a method of manufacturing such a pressure-sensor-integrated glow plug.

When only smoke is generated, the sensor sensitivity is not substantially changed from the initial value. When both smoke and unburned HC are generated, the number of times the sensor sensitivity becomes lower than the initial value is increased. From these results, it can be understood that a deposit is formed in the presence of unburned HC and smoke existing simultaneously. The degree of reduction in sensor sensitivity becomes higher if the smoke concentration is increased when the unburned HC concentration condition is fixed. From this result, it can also be understood that while the coexistence of smoke and unburned HC is a prerequisite, unburned HC contributes largely to the formation of a deposit.

A glow plug including a substantially cylindrical housing extending in an axial direction; a rod-shaped heater unit having a front end protruding from the front end of the housing and movable in the axial direction; a connecting member connecting the heater unit to the housing within the housing and allowing the heater unit to move in the axial direction; and a pressure sensor that detects pressure received by the heater unit. The heater unit has a large-diameter portion at the rear end thereof and a small-diameter portion frontward of the large-diameter portion and having a diameter smaller than the diameter of the large-diameter portion. The connecting member connects the small-diameter portion of the heater unit to the housing within the housing.

A glow plug includes a cylindrical housing, a rod-shaped heater, a membrane portion, and a pressure sensor. The cylindrical housing extends along an axial direction. The rod-shaped heater extending along the axial direction is displaced along the axial direction and has one end portion disposed within the housing, and an other end portion which is exposed from the housing. The membrane portion connects together the heater and the housing and has a multi-layer construction which has a first layer and a second layer of which at least part is positioned nearer to the other end portion in the axial direction of the heater than the first layer. The pressure sensor measures a pressure within a combustion chamber in which the other end portion is disposed by making use of a displacement of the heater. A thickness of the second layer is larger than a thickness of the first layer.

Described is a method for regulating the temperature of a glow plug of an internal combustion engine, wherein a target resistance is determined from a target temperature by means of a resistance temperature characteristic of the glow plug and the actual resistance of the glow plug is regulated to the target resistance, the glow plug is heated to determine the resistance temperature characteristic of the glow plug, and thereby determining a resistance gradient and an electrical resistance of the glow plug is measured before the heating or at a defined time during the heating, using both the measured resistance and the resistance gradient, the resistance temperature characteristic is determined.

A system for an engine to determine in situ under specified conditions the auto-ignition quality of the fuel used in a compression ignition engine is provided. The system may include an ion current sensor. The ion current sensor may access an engine cylinder for obtaining ion current data. A control unit may be in communication with the ion current sensor for receiving the ion current data. The control unit being configured to determine the auto-ignition quality of the fuel based on features of the ion current data.

A heater includes a ceramic body of bar shape; and a heat-generating resistor disposed in an inside of the ceramic body, when viewed in a transverse section, the heat-generating resistor including at least one step portion provided in an outer periphery part of the heat-generating resistor, the at least one step portion having such a shape that semicircular portions bisected in a diametrical direction of the heat-generating resistor deviate from each other along the diametrical direction.

An aerosol delivery device is provided that includes at least one housing enclosing a reservoir configured to retain an aerosol precursor composition. The device includes a heating element, and a microprocessor configured to operate in an active mode in which the control body is configured to control the heating element to activate and vaporize components of the aerosol precursor composition. And the device includes a heart rate monitor including a plurality of biopotential electrodes affixed to the housing and configured to obtain biopotential measurements from a user, and including signal conditioning circuitry configured to produce an electrocardiogram signal from the biopotential measurements. The microprocessor is coupled to the signal conditioning circuitry and further configured to control operation of at least one functional element of the aerosol delivery device based on the electrocardiogram signal or a heart rate of the user calculated therefrom.