Thermocouple Input Terminal With Integrated PCB Sensor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing thermocouple input terminals face challenges in accurately measuring cold junction temperature due to high material costs, assembly difficulties, and poor performance in harsh conditions, leading to significant isothermal errors and increased complexity.
Innovation Solution
A cold-junction-compensated input terminal design featuring a printed circuit board (PCB) with integrated thermal sensors and board-to-board connectors, eliminating the need for metal pins and simplifying assembly by using PCB traces for signal transmission, thereby reducing thermal impedance and improving measurement accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional metal pins and separate CJC sensors are used in input terminals, then reliable electrical connection is achieved, but material cost increases and assembly becomes difficult
Solution Approach 1:
The patent combines the electrical connection function and temperature sensing function into a single integrated PCB structure. The PCB implements both the electrical pins for signal transmission and the CJC temperature sensor in one unified component, eliminating the need for separate metal pins and discrete sensor mounting operations. This integration directly resolves the contradiction by maintaining reliable electrical connection while dramatically simplifying assembly.
Solution Approach 2:
The patent replaces traditional mechanical metal pins with PCB-trace-based electrical connections. Instead of using separate metal components that require mechanical assembly, the electrical connection path is formed through PCB traces and plated through-holes, which are created during PCB manufacturing. This substitution eliminates complex mechanical assembly steps while maintaining reliable electrical connectivity.
2Reliability
If separate CJC sensors and metal pins are used, then electrical connection is reliable, but device complexity increases
Solution Approach 1:
The patent merges multiple functions (electrical connection, temperature sensing, signal transmission) into a single integrated PCB structure. This consolidation reduces the number of discrete components and interconnections required, directly addressing the device complexity issue while maintaining reliable electrical connection through the integrated design.
3Measurement precision
If thermal sensors are mounted on PCB near cold junction, then measurement accuracy improves, but thermal impedance increases compared to direct metal pin contact
Solution Approach 1:
The patent applies local quality by creating a high-thermal-conductivity path specifically at the cold junction location through plated through-holes and copper pours on the PCB. This localized thermal management ensures that the CJC sensor mounted on the PCB surface can accurately measure the cold junction temperature by conducting heat efficiently from the insertion point through the PCB structure to the sensor location, thereby minimizing thermal impedance in the critical measurement path.
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
This design enhances measurement accuracy, reduces component costs, and simplifies assembly, providing a cost-effective and reliable solution for thermocouple input terminals by integrating thermal sensors directly on the PCB and using PCB traces for signal transmission, thus minimizing isothermal errors.
Implementation Method 1
a thermal sensor, mounted on the PCB, and configured to measure temperature at or near a cold junction of the input terminal
Implementation Method 2
a first plurality of traces connecting the input portion of the PCB to the output portion of the PCB, and configured to send TC signals to the thermocouple instrument
Data Source
AI summary
Input terminal of a thermocouple (TC) instrument. The input terminal may include a printed circuit board (PCB), including an input portion configured to receive signals from a thermocouple, and an output portion configured to communicatively connect to the instrument. The input terminal may further include a sensor mounted on the PCB, configured to measure temperature at or near a cold junction of the input terminal. The PCB may include first traces connecting the input portion of the PCB to the output portion of the PCB, and configured to send TC signals to the TC instrument and second traces connecting the sensor to the output portion of the PCB, and configured to send temperature signals to the instrument. The traces may be configured to provide the TC signals and the temperature signals to the TC instrument without using metal pins.