1. MECH 322 Instrumentation Lab 7 Computer Data Acquisition System for Steady Thermocouple Signals Performed: March 6, 2007 Group 0 Miles Greiner Lab Instructors: Mithun Gudipati, Venkata Venigalla

2. ABSTRACT The temperature of boiling and room-temperature water, and an ice/water bath were measured using a mercury-in- glass thermometer and a computer data acquisition system. Measurements from both instruments were in agreement for all three baths. The measure boiling water temperatures were in agreement with the predicted saturation temperature at the measured barometric pressure.

3. Figure 1 Type J Thermocouple Temperature versus Voltage The equation to find the thermocouple voltage from the output of the signal conditioner is V TC = V Out /0.105143 V/mv -4.632 mv The equation to find the thermocouple temperature from its voltage is in the figure These equations are used in the LabVIEW program to determine the temperature

4. Figure 2 VI Front Panel

5. Figure 3 VI Block Diagram

6. Fig. 4 Measured Temperature versus Time The measured temperatures are fairly constant

7. Table 1 Measured and Predicted Temperatures This table presents the computer data acquisition system and thermometer measured temperatures for the three baths. The temperatures from both measurement devices are in agreement for all three baths The saturation temperature at the measured barometric pressure of P atm = 87 kPa is 95.6 o C (Reynolds, W.C. and Perkins, H.C., Engineering Thermodynamics, 2nd edition, McGraw Hill, 1977). This is within the confidence interval of the boiling water temperature for both measurement techniques.