SLAA976 October   2020 MSP430FR5041 , MSP430FR5043 , MSP430FR6005 , MSP430FR6007 , MSP430FR6041 , MSP430FR6043 , MSP430FR6045 , MSP430FR6047

 

  1.   Trademarks
  2. 1Introduction
  3. 2Setup and Configuration
    1. 2.1 EVM430-FR6043 GUI Configuration
  4. 3Test Results
  5. 4Extracting O2 Concentration
    1. 4.1 Note on Achieved Accuracy
  6. 5OpenSCAD 3D Test Fixture
  7. 6References

2 Setup and Configuration

The EVM430-FR6043 is used with two Jiakang 200 kHz transducers. A 3D printed fixture is used to mount the transducers for experimentation.

The system diagram depicted in Figure 2-2 shows the use of the TMP117EVM to measure temperature. Based on Equation 3, you can see that concentration is dependent on temperature. In fact, for every 1°C measurement error in the system, we are introducing ~2.75% error in our oxygen concentration readings. Hence, a 0. 1°C accurate temperature sensor such as the TMP117 is recommended.

For simplicity purposes, because the temperature was constant in this experiment, temperature was only sampled once. The temperature in this experiment was found to be 22.7 °C (295.85 K). When calculating the concentration or speed of sound in a gas medium using the equations describe in this document, be sure to use degrees Kelvin as the unit of temperature.

GUID-20201015-CA0I-TNSD-QB5M-6D3KLKFPWBQF-low.jpg Figure 2-1 Printed Fixture and EVM Implementation
GUID-20201015-CA0I-SBZZ-ZCCN-Z1NB3HWLCHT9-low.png Figure 2-2 System Diagram