Temperature measurement using an RTD sensor.
RTD a = 0.00375
R0 of RTD = 320 Ohms @ 25°C.
Temperature expected = 60°C
Input voltage = 20V.
For a voltage divider: Expected Vout = 11V @ 60°C
Use a bridge to measure the assigned quantity. Use the value of R0 as the value for the rest of the resistors in the bridge.
1.2.2. Draw and describe the circuit and its elements. What are the elements? How are they connected? How would you power it? How does it work? How can you prove it is working? Etc.
1.2.3 How is Vout related to Vin? Present an equation with all variables needed that will help you calculate this.
1.2.4 Using the equation above, evaluate Vout when the system is unexcited. Is Vout zero when the system is unexcited? Why? If yes/no, what are the implications?
1.2.5 Present a proof calculation.
1.2.6 Sketch the trend of change in Vout vs change in resistance.
1.2.7 What is the sensitivity? What does this sensitivity tell us?
1.2.8 Propose an amplification circuit using a real differential amplifier with a CMRR of 92dB. The voltage read by an ADC following your circuit is 0-5V, and you want to use 3V for the expected measurand (force - task A or temperature - task B).
1.2.9 In preliminary testing, it has been discovered that the wiring provided by the company for your circuit is acting as an antenna, picking up Electromagnetic Interference (EMI) which, combined with your circuit, produces an unwanted signal of 500mV with an 80Hz frequency and above. Propose how to attenuate this unwanted signal. What circuit would you recommend using? Where would you put this circuit? (before sensor, after sensor, before amplification, after amplification?) What are the minimum elements needed? Present a drawing of this circuit for removing EMI and its frequency response plot.
1.3 When would you recommend a voltage divider over a bridge circuit? And vice versa.