DESIGN AND CONSTRUCTION OF PC BASED DIGITAL THERMOMETER

Presentation on DESIGN AND COSTRUCTION OF PC BASED DIGITAL THERMOMETER

 

 

Objectives

1. Determine characteristic Equation of thermistor
2. Sensing and measuring temperature and convert temperature change into electrical quantity as voltage
3. Analog to Digital Converter(ADC) for digital output
4. Multiplexing for converting ADC output from parallel to serial
5. Data Acquisition by Computer
6. Determine and display the Temperature.

Block diagram for measuring temperature

Advantages of Thermistor

High positive or negative temperature coefficient. Greater temperature range (-10⁰ C to 100⁰ C). Higher stability & Precision Size. Higher sensitivity. Comfortable of working. Commercially available at very low price

Temperature versus resistance curve of thermistor

Equation of the curve from MATLAB

R(T)=-0.00001632 T ³+0.02654 T ²-1.504T +32.5

Temperature sensor

Temperature versus voltage of differential amplifier

Non inverting amplifier

Data acquisition circuit

Our data acquisition arrangement

Application of PC based temperature measurement

1. Continuous Temperature monitor and analysis for weather forecasting
2. Automatic Process Control of Boiler System
3. Continuous temperature monitoring and analyzing Central Air Condition System
4. Space ship
5. Measure , monitoring and analyze Human body temperature in medical technology
6. Temperature monitoring and control of various temperature process

Advantages of PC measuring

1. Previous data can be stored
2. Easy operation Technique
3. Available
4. Cost effective

Submitted By MD.MAINUL HOSSAIN and FOIZ AHMED