Immersion Probe Reference Circuit for Contact Resistance Error Detection
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Solution Overview
Problem
Existing immersion probes used in the steel-producing industry for detecting molten metal status variables are prone to measurement errors due to signal corruption from transition resistances and inadequate thermal insulation, leading to incorrect process management and safety risks during ongoing metallurgical processes.
Innovation Solution
A probe with a built-in reference circuit that generates and outputs reference voltages to check the measuring circuit for errors, allowing for continuous operation and error detection, which can be used to determine offsets or support point fields for accurate measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If disposable probes with wound cardboard are used for immersion in molten metal, then the probes can be easily manufactured and discarded after use, but the cardboard chars during measurement and deposits combustion residues on mating contacts, causing significant changes in contact resistance and measurement errors
Solution Approach 1:
The patent extracts the reference voltage generation function from the probe body by using the special contact that connects to a dedicated reference contact on the lance. This separates the reference voltage source from the probe's disposable cardboard structure, eliminating the charring problem while maintaining ease of probe manufacturing. The reference voltage is now provided by the lance's robust contact system rather than the probe's temporary cardboard structure.
Solution Approach 2:
The patent introduces an intermediary reference contact on the lance that mediates between the probe's special contact and the evaluation unit. This intermediary provides a stable, non-charring reference point through which the reference voltage can be transmitted without being affected by the probe's combustible cardboard material, thus maintaining measurement accuracy.
2Reliability
If manual testing of mating contacts is performed during production breaks, then the measuring circuits can be checked for faultlessness, but the operator must enter hazardous areas and tests cannot be performed during ongoing metallurgical processes
Solution Approach 1:
The patent enables the measuring circuit to perform self-verification by automatically generating reference voltages through the special contact and comparing them with actual measurement signals. This eliminates the need for manual operator intervention, allowing continuous automated testing during ongoing metallurgical processes without requiring operators to enter hazardous areas or interrupt production.
Solution Approach 2:
The patent implements feedback by continuously monitoring the reference voltages generated through the special contact and comparing them with actual measurement signals. This automatic feedback mechanism verifies measuring circuit faultlessness in real-time during production, maintaining reliability without interrupting process continuity.
3Reliability
If reference voltages are generated by the probe itself, then continuous checking of measuring circuits is enabled during ongoing processes, but the probe structure and complexity increase
Solution Approach 1:
The patent makes the special contact serve multiple functions: it acts as both a signal transmission contact for measurement data and a reference voltage output contact for circuit verification. This multi-functionality enables continuous checking of measuring circuits without adding separate reference voltage generation components to the probe structure, thus maintaining simplicity while achieving continuous verification.
Data Source
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Figure 7~8
AI summary
A probe (1) for a lance (2) for dipping into a metal melt (4) is substantially rotationally symmetrical, in particular cylindrical, with respect to a probe axis (5). The probe (1) can be fitted onto the lance (2) of the metallurgical vessel (3) by being fitted on in the direction of the probe axis (5). The probe (1) has a number of signal contacts (6) and a number of other contacts (7), which, when the probe (1) is fitted onto the lance (2), are contacted with respective mating contacts (8) of the lance (2). The probe (1) has a reference circuit (9), which is designed in such a way that it generates a number of reference voltages (U) per signal contact (6) and outputs same to the corresponding respective contacts (8) via the respective signal contacts (6). The probe has a switchover device (15), which in a first switched state connects the reference circuit (9) and in a second switched state connects the sensor devices (14), instead of the reference circuit (9), to the signal contacts (6).