Ionisation Sensor Calibration Without Flame

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing sensors for measuring ionization of gas flames require calibration during operation, which is inefficient and consumes fuel, and do not account for electrode aging, affecting measurement accuracy.

Innovation Solution

A sensor with precisely defined electrodes and a built-in voltage source allows for calibration without a gas flame, using a test voltage to determine electrode sensitivity, and stores characteristic curves for adjusting measurements based on test currents, enabling independent calibration and accounting for electrode aging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If calibration is performed during operation of the heating system, then measurement accuracy is maintained, but fuel consumption increases and calibration cannot be performed automatically

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidfuel consumption
Core Design Contradiction:
Measurement precisionVSLoss of energy

Solution Approach 1:

The patent applies preliminary action by performing calibration during a test phase before normal operation, using a voltage source to create ionization conditions without requiring actual combustion. This allows the sensor to be calibrated in advance using test currents and stored characteristic curves, eliminating the need for fuel-consuming calibration during operational phases while maintaining measurement accuracy

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If the sensor requires calibration during heating system operation, then measurement sensitivity can be adjusted, but the calibration process becomes manual and time-consuming

Engineering Contradiction:
Improvemeasurement sensitivityVSAvoidcalibration convenience
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent implements self-service by enabling the sensor to perform its own calibration automatically during a test phase. The measurement circuit determines test currents and stores characteristic curves without external intervention, allowing the sensor to self-calibrate using built-in voltage sources and memory storage, thereby eliminating manual calibration requirements and reducing time consumption

Inventive Principle:
Principle #25Self-service

3Device complexity

If electrode aging is not accounted for, then the sensor structure remains simple, but measurement accuracy deteriorates over time

Engineering Contradiction:
Improvesensor structureVSAvoidmeasurement accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent applies parameter changes by monitoring test current values over time to detect electrode aging effects. The measurement circuit stores multiple characteristic curves corresponding to different electrode conditions and selects appropriate curves based on measured test currents, thereby compensating for aging-induced parameter changes and maintaining measurement accuracy without requiring complex structural modifications

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables accurate ionization measurement and automatic calibration of the sensor outside operational conditions, reducing fuel consumption and maintaining measurement precision by accounting for electrode aging.

Implementation Method 1

a voltage can be generated at which the air is ionized even without a gas flame

Methodology Applied
Scientific EffectIonization: Ionisation

Data Source

PatentEP2871473B1Ionisation sensor
Publication Date: 2020.07.08 ROBERT BOSCH GMBH
  • EP2871473B1 patent drawingFigure 1~2

AI summary

The invention relates to a method for calibrating a sensor (1) and a sensor (1) for measuring the ionization of a gas flame (10), wherein two electrodes (3,4) are provided, wherein the two electrodes (3,4) are arranged on a housing (2) of the sensor (1), wherein the electrodes (3,4) are connected to a voltage source (6), wherein the voltage source (6) is configured to generate a voltage at which an ionization of the air is generated without a gas flame.