Glow Plug Resistance Calibration for Accurate Temperature Control

The patent applies preliminary action by measuring the cold resistance of the glow plug before heating and using this initial value to calculate the resistance temperature characteristic. This eliminates the need to heat the glow plug to equilibrium for measurement, as the cold resistance measurement provides sufficient baseline data when combined with resistance gradient measurements during subsequent heating phases.

Instead of heating the glow plug to full equilibrium temperature for measurement purposes, the patent uses partial heating with continuous resistance gradient measurement. The resistance gradient is measured during the heating process itself, allowing the system to determine the resistance temperature characteristic without requiring complete thermal equilibrium, thus reducing the measurement time from about one minute to a much shorter duration.

The patent applies self-service by utilizing the glow plug's own heating process as the measurement process. The resistance gradient is measured during the normal heating operation of the glow plug, and the cold resistance is measured in the existing cold state. This eliminates the need for separate, complex equilibrium heating setups and expensive measurement equipment, as the glow plug's normal operational characteristics are used for self-characterization.

The patent replaces the mechanical/thermal equilibrium-based measurement system with an electrical measurement system. Instead of requiring thermal equilibrium and complex thermal measurement setups, the system uses electrical resistance measurements and resistance gradient calculations during the heating process. This substitution of electrical measurements for thermal equilibrium measurements simplifies the manufacturing and measurement process while maintaining accuracy.