Process Transmitter Housing Moisture Detection by Thermal Conductivity

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Solution Overview

Problem

Existing process control transmitters in industrial environments face issues with moisture detection, leading to output errors and potential failure due to environmental exposure, with current methods being unreliable and prone to false alarms.

Innovation Solution

A process pressure transmitter equipped with a liquid detector using thermal conductivity to detect moisture within the transmitter housing, which is less susceptible to electrical contamination and condensation, employing a temperature sensor and heating element to differentiate between dry and wet environments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If electrical conductivity sensors are used to detect moisture, then moisture detection capability is provided, but the system becomes sensitive to contamination and leakage currents causing false alarms

Engineering Contradiction:
Improvemoisture detection accuracyVSAvoidfalse alarm rate
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces electrical conductivity-based moisture detection with thermal conductivity-based detection. The temperature sensor measures thermal properties of the environment rather than electrical properties, making it immune to electrical contamination and leakage currents that cause false alarms in conventional sensors.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the detection parameter from electrical conductivity to thermal conductivity. By measuring temperature and thermal energy dissipation rather than electrical current, the system achieves reliable moisture detection without sensitivity to electrical contamination.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If manual diagnostic operations are used to detect moisture, then detection capability is provided, but the process is reactive and requires removing the transmitter from control loop

Engineering Contradiction:
Improvemoisture detection capabilityVSAvoidoperational continuity
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The transmitter performs self-diagnosis for moisture detection through the integrated temperature sensor and controller. The system automatically monitors its own environmental conditions and detects moisture presence without requiring external manual intervention or removal from the control loop.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The controller continuously receives temperature sensor signals and automatically processes them to detect moisture conditions. This closed-loop feedback system provides ongoing monitoring and immediate detection of moisture without interrupting normal transmitter operation.

Inventive Principle:
Principle #23Feedback

3Adaptability or versatility

If process control transmitters are field mountable for process monitoring, then process variable measurement capability is improved, but environmental moisture can enter the housing causing output errors and failure

Engineering Contradiction:
Improvefield mounting capabilityVSAvoidenvironmental moisture damage
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The temperature sensor continuously monitors the internal environment of the transmitter housing before moisture can cause damage. By detecting moisture presence early through thermal conductivity changes, the system can alert operators before output errors or component failure occur.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The temperature sensor acts as an intermediary detection element that indirectly senses moisture presence by measuring thermal conductivity changes in the housing environment, rather than directly contacting potential moisture sources.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Accurately detects the presence of moisture or fluid within the transmitter housing, reducing the risk of damage and output errors, while minimizing false alarms and ensuring reliable operation in humid or flooded conditions.

Implementation Method 1

A liquid detector is coupled to the transmitter housing. The liquid detector includes a temperature sensor configured to generate signals indicative of a presence of liquid within the transmitter housing

Methodology Applied
Scientific EffectThermal conductivity: Conduction (thermal)

Data Source

PatentEP3857173B1Electronics housing with thermal fluid detection
Publication Date: 2024.08.28 ROSEMOUNT INC
  • EP3857173B1 patent drawingFigure 1
  • EP3857173B1 patent drawingFigure 2
  • EP3857173B1 patent drawingFigure 3

AI summary

A process transmitter (100) includes a transmitter housing (108) and a liquid detector (128, 302) coupled to the transmitter housing (108). The liquid detector (128, 302) includes a temperature sensor (402) configured to generate signals indicative of a presence of liquid within the transmitter housing (108). The process transmitter (100) also includes a controller (122) coupled to the liquid detector (128, 302) configured to receive the generated signals, determine the presence of liquid within the transmitter housing (108) based on the received signals, and generate an output indicative of the determined presence of liquid within the transmitter housing (108).