A Simple Approach to Connecting Pt100 by Utilizing an Electroacoustic Resonance Tube

Area of Science:

• Electrical Engineering
• Acoustics
• Sensor Technology

Background:

• Pt100 sensors are crucial for industrial temperature monitoring.
• Existing signal conditioning methods can be complex and require specialized hardware.
• A need exists for simpler, more accessible temperature sensing solutions.

Purpose of the Study:

• To propose and validate a novel electroacoustic signal conditioning technique for Pt100 temperature sensors.
• To demonstrate the feasibility of using a resonance tube and an electroacoustic transducer for temperature measurement.
• To evaluate the performance and advantages of the proposed system compared to conventional methods.

Main Methods:

• A resonance tube filled with air was used as the signal conditioner, operating in free resonance mode.
• Pt100 sensor wires were integrated with a speaker, where resistance changes with temperature.
• An electrolyte microphone detected the standing wave amplitude, with signals acquired via LabVIEW.
• A virtual instrument was developed for voltage measurement and data analysis.

Main Results:

• A direct correlation was established between the standing wave amplitude and Pt100 resistance changes due to temperature variations.
• The system demonstrated a maximum nonlinearity error of approximately 3.77% at full-scale deflection.
• Experimental results and a regression model confirmed the accuracy of the developed signal conditioner.

Conclusions:

• The proposed electroacoustic method provides a simple and effective means for Pt100 signal conditioning.
• The system allows direct interfacing with personal computers using standard sound cards, eliminating the need for extra measuring tools.
• This approach offers advantages in simplicity and cost-effectiveness over traditional Pt100 signal conditioning techniques.