- Uses at least 2 sensors: Temperature, Ultrasonic, and Turbidity
- Waterproof housing
- Thermometer touches water, able to test at different depths
- Thermometer is stationary in how far it is away from the edge of the canal
- Visual aid/representation via LEDs, easily visible
- 2 (at least) 3-D printed part
- Calibrate the turbidity sensor
- External light source/amount of light to pass through water into turbidity sensor
- Power source
- Data uploaded regularly
- Able to turn on LEDs based on values from thermometer and turbidity sensor
- Computer does not fall in Ala Wai
- Supplies power
First, turbidity is a property resulting from particles that are suspended in water, rather than dissolved. There is a direct relationship between water temperature and turbidity as increased levels of turbidity raises temperature because heat is absorbed by the suspended particles. This is one factor that promotes the optimal temperature for the Vibrio vulnificus to grow in. Higher turbidity can have a negative effect on the environment. With more particles in the water, it can reduce the amount of light penetrating the water. Also, sudden changes in turbidity suggests that there is a possible new source of pollution into the water.
Water turbidity is measured by using a nephelometer which is a device used to measure both the size and concentration of particles in a liquid. The nephelometer achieves this by using a light beam. Light scatters in contact with suspended particles, and there is a light detector that detects the amount of light that is reflected back at it. This is used to determine the amount of particles, or particle density, in the water. Higher turbidity levels results in murky water due to the increased number of particles. High turbidity levels usually results from runoff from land which can contain pollutants and harmful contaminants. This includes sewage, micro-organisms, and chemicals. The Regional Ocean Modeling System (ROMS)'s Ocean Circulation Model gathers results around Waikiki and also uses turbidity measurements from the Manoa-Palolo stream flowing into the Ala Wai Canal.
Like mentioned earlier, the more particles in the water causes less light to penetrate. If more light is detected in the light detector, it means that there are more particles in the water. The unit of measurement for turbidity is NTU, or Nephelometric Turbidity Units. The unit of measurement for suspended solids is PPM, or parts per million. To compare with results at the end of this engineering process, regular drinking or clean water should have levels as low as 0.1 NTU.
After determining the issues the Ala Wai is facing, my team decided to test the turbidity and temperature of the Ala Wai. The problem is determining how to use a turbidity sensor to measure the haziness and cloudiness of water, caused by particles that could potentially be hazardous, and gather data from the Ala Wai's waters.
This is my first blog and I'll be using this for my robotics design project.
Class of 2021