1. P13625 – Indoor AIR Quality Monitor
Presented by:
Mechanical Engineers:
-Rachelle Radi
-Kyle Sleggs
Industrial Engineer: -Jeff Wojtusik
Electrical Engineers:
-Alem Bahre Gessesse
-Shafquat Rahman
Computer Engineer:
-Daniel Bower
Faculty Guide:
-Sarah Brownell

2. Agenda Project Description Customer Needs & Specs System Architecture
Development Process
Concept Selection
Final Design
Budget
Testing
Outcomes
Future Improvements

3. Project Description UCB- Particulate and Temperature Sensor
Design an air quality monitor capable of collecting a wider range of relevant environmental factors than the UCB-PATS sensor currently in use
Develop mounting methods and other techniques for collecting reliable data on site
Create a system capable of gathering data remotely without external power for several days
UCB- Particulate and
Temperature Sensor
Indoor Air Quality Monitor

4. Customer Needs

5. Engineering Specifications

6. System architecture

7. Project TimeLine Current Project Status Phase 0: Planning
Define Project Goal
Develop Customer Needs
Define Specifications
Phase 1: Concept Selection
PUGH Concept Selection
Testing of Selected Sensors 1
Phase 2: Product Design
Validation of design through simulation and breadboard builds 2
Phase 3: Final Design
Detailed schematics & drawings
Finalized BOM 3
MSD 1
Phase 4: Building & Refining
Order parts
Electrical Testing
Final Assembly 4
Phase 5: Testing
Multiple tests
Documentation 5
MSD 2
Current Project Status

8. Concept Selection
Sensors: CO PM
Temperature & Humidity
Case
Assembly Method
Hanging Options

9. Final design 6”x6”x4” Repurposed Conduit Box
PM, CO, Temp & Humidity Sensors
Two acrylic plates:
1 for Sensor Positioning
1 for User Interface
Basic “core” held together with M4 threaded rod
Secured into case with L-brackets and screws

10. Layout 5V Voltage Regulator & 3.3V Voltage Heat Sink Regulator
Temperature
& Humidity
Sensor
Particulate
Matter Sensor
Microcontroller
Carbon
Monoxide
Sensor SD
Card
UART
Module

11. Budget
$1000 Budget
$1.82 of the budget remains after experimentation, building, and testing.
Able to build 2 monitors
Compare to the UCB-PATS monitor, the Indoor Air Quality Monitor (IAQM) is effectively $65 less
More functionality (Humidity and CO)
USB connection cable on IAQM is more readily available and modern than serial connection cable.

12. Testing Results Test 1 – CO Sensor Calibration (Not Conducted)
Test was not conducted due to lack of safe testing facilities and the potential health hazards to team members
Test 2 – Environmental Test (Passed)
While lacking access to the environmental test chamber the team was able to show expected changes in data over a range of small tests.
Test 3 – Microcontroller Sensor Communication Test (Passed)
The reading and acknowledgement means that a single reading can be done in 13 ms (77 readings per second)
Test 4 – Monitor Endurance Test (Passed)
While the monitor failed a live test due to software issues, the theoretical life span of the batteries is 9.1 days was calculated using measured power consumption.
Test 5 – Survey Test (Passed)
There were 21 surveys completed to compile data on the style and usability of the Indoor Air Quality Monitor. All of the survey points resulted in a average between 7.6 to 8.3 (on a scale of 1 to 10).

13. Monitor Endurance Test
Monitor experienced a software error during the initial endurance testing.
This test lasted for an initial 68 hours and 4 minutes.
This forced the team to find alternative testing methods due to a time shortage.
The batteries used during the initial testing were then removed and measured for remaining voltage.
7.785V was the remaining potential in the battery packs
This allowed for an average circuit load of mA to be calculated
The remaining useful life of the battery packs could then be calculated
Batteries considered “used” with 5.1 V remaining
With a potential drop of 1.215V
Hours OR Days

14. Environmental Test
15 Minute Test
180 Readings
1 Reading Every 5 s

15. Environmental Testing w/ CO
12 Minutes of Testing
140 Readings
1 Reading Every 5 s

16. Testing Results Test 6 – Drop Test (not conducted)
The drop test was not completed at this time due to the fragile nature of the sensors within the monitor
Test 7 – Computer Interfacing Time Test (Passed)
The monitor transfer a complete set of data in approximately 6.5 seconds
Test 8 – Mounting Test (Passed)
The team was able to test and document 5 different ways of mounting the monitor to various surfaces
Test 9 – Footprint and Height (Passed)
The footprint and height of the monitor are cm^2 and cm respectively, which falls into our specifications of 400 cm^2 and 10 cm
Test 10 – Cost Analysis (Passed)
The total cost of the monitor is $435 (parts and labor)
Test 11 – Reusability (Passed)
The expected lifetime of the monitor (determined by individual component life expectancy) is approximately 2.28 years

17. Comparison of Monitors
UCB-PATS
Cost: $500
Functionality:
Particulate Matter
Temperature
Serial Computer Interface
Uses one 9V battery
Indoor Air Quality Monitor
Cost: $435
Functionality:
Particulate Matter
Temperature
Carbon Monoxide
Humidity
USB Computer Interface
Uses twelve AA batteries

18. Future Improvements Improve Battery Life of Monitor
Increase Proven Accuracy of Data Collected
CO sensor with analog not binary type of output
Continuous data measurements (time history data)
Different type of Particulate Matter (PM) sensor (ionization versus optical sensors)
Design and build testing chamber that would allow accurate control and recording of the temp, humidity, PM, and CO concentrations
Improve overall lifetime of monitor
Incorporate SD card for larger quantity of measurements
Integration of mobile device to accelerate data transfer in the field
Research into alternative case materials that may not insulate as well as the current case

19. Acknowledgements Sarah Brownell Faculty Guide Help with design process
Help with understanding the challenges that impoverished nations face
Dr. James Myers
Assistance with understanding what researchers are looking for in an Air Quality Monitor
Input on design and functionality
Mr. Rob Kraynik
Provided technical advice in the construction and manufacturing of the monitor
Mr. George Slack
Supporting the design stage of the electrical circuit
Multidisciplinary Senior Design Department
Provided funding for research and monitor construction

20. Questions?