Glow plug arranged for measuring the ionization current of an engine

A glow plug for diesel engines, comprising:

• a metal tubular body;
• a metal sheath carried by the tubular body and having an end portion projecting from the tubular body, in which the metal sheath is electrically insulated from the tubular body;
• a first electrical terminal having the shape of a metal rod extending through the tubular body and having an end inserted inside the aforesaid sheath;
• a heating resistor set inside the aforesaid sheath, the heating resistor being electrically connected to the first terminal and to the aforesaid end portion of the sheath;
• a second electrical terminal electrically connected to the sheath and disposed coaxially with respect to the first electrical terminal;
• and
• an insulating tubular element set coaxially between the first terminal and the second electrical terminal.

A glow plug for diesel engines, comprising:

• a metal tubular body;
• a metal sheath carried by the tubular body and having an end portion projecting from the tubular body, in which the metal sheath is electrically insulated from the tubular body;
• a first electrical terminal having the shape of a metal rod extending through the tubular body and having an end inserted inside the aforesaid sheath;
• a heating resistor set inside the aforesaid sheath, the heating resistor being electrically connected to the first terminal and to the aforesaid end portion of the sheath;
• and
• a second electrical terminal electrically connected to the sheath and disposed coaxially with respect to the first electrical terminal,
• characterized in that the second electrical terminal extends into a through hole formed inside the first terminal.

A glow plug for diesel engines, comprising:

• a metal tubular body;
• a metal sheath carried by the tubular body and having an end portion projecting from the tubular body, in which the metal sheath is electrically insulated from the tubular body;
• a first electrical terminal having the shape of a metal rod extending through the tubular body and having an end inserted inside the aforesaid sheath;
• a heating resistor set inside the aforesaid sheath, the heating resistor being electrically connected to the first terminal and to the aforesaid end portion of the sheath;
• and
• a second electrical terminal electrically connected to the sheath and disposed coaxially with respect to the first electrical terminal,
• characterized in that the second terminal comprises a tubular element set coaxially to the outside of the first terminal.