The present disclosure is directed to a heater including: a resistor including a heat-generating portion; a lead joined to an end portion of the resistor; and an insulating base covering the resistor and the lead. The heater includes a connection portion in which the resistor and the lead overlap each other in a direction perpendicular to an axial direction of the lead, and a boundary between the resistor and the lead has a curved shape when the connection portion is seen in a cross section perpendicular to the axial direction.

A glow plug includes a housing having an axial hole extending in an axial line direction; a ceramic heater that is relatively displaceable with respect to the housing along the axial line direction and has at least outer surface made of ceramic; and a pressure sensor fixed to the housing and configured to output a signal based on the relative displacement of the ceramic heater. A fixed member fixed to the ceramic heater while the ceramic heater is arranged to an inner circumference of the fixed member. A welded member is welded to an outer circumference of the fixed member. An inner circumferential surface of a portion of the fixed member to which at least the welded member is welded is spaced apart from the outer surface of the ceramic heater.

A glow plug including a heater (200) having a rear heat-generating element (260) formed of a resistance heat-generating element, and provided in an axial region thereof between a forward end (136) of a housing and a rear end (315) of a displacement member (300) located rearward of the forward end (136). The heat-generating element (260) is arranged separately from a forward heat-generating element (205) provided at a forward end portion of the heater.

A method for operating a glow plug includes controlling a temperature of the glow plug by switching between applying a voltage V.sub.H and applying a voltage V.sub.N<V.sub.H to the glow plug. Applying the voltage V.sub.H and applying the voltage V.sub.N causes a glow plug current to oscillate about a glow plug current threshold. The glow plug current threshold is associated with one of the voltage V.sub.H and the voltage V.sub.N. The method includes monitoring the glow plug current at the one of the voltage V.sub.H and the voltage V.sub.N.

A method of sealing a glow plug of a fuel cell system, the glow plug including a housing and a heating element extending from a first end of the housing. The method includes inserting the heating element into a sealing element having an annular base and a tubular collar extending from the base and forming a fluid-tight connection between the glow plug and the fuel cell system by attaching the collar to the heating element and by attaching the base to the first end of the housing.

A heater includes: a ceramic body having a rod-like shape, including an end face and an outer periphery face; and a heat generating resistor embedded in the ceramic body, a surface roughness of the end face of the ceramic body being larger than a surface roughness of the outer periphery face of the ceramic body.

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 glow plug adaptor for pressure measurement in a combustion chamber of an internal combustion engine includes an adaptor sleeve attached to an adaptor head that contains a pressure sensor with a diaphragm. A sealing shoulder can be screwed into an opening in a combustion chamber to provide a pressure-tight seal and permit passage of signal conductors from the pressure sensor through the adaptor sleeve. The adaptor head is tapered at the proximal combustion chamber end, and in the adaptor head a cavity is formed in such a way that the cavity is bounded by the diaphragm of the pressure sensor mounted therein and by a closed end wall of the adaptor head.

A control apparatus (100) controls a diesel engine (10). A glow plug (32) which can detect cylinder pressure is provided on the engine (10). An ECU (70) computes a parameter related to a change in cylinder pressure obtained from the glow plug (32). The ECU (70) controls fuel injection timing such that the parameter falls within a target range when combustion in the engine (10) is switched from premixed combustion to diffusion combustion.

A ceramic heater-type glow plug that includes a ceramic heater, and a metallic outer cylinder, one end side of which holds the ceramic heater and the other end side of which is inserted in and fixed to an inner hole of a housing.