1. Jalpa Shah and K. Kala Drake
BSCI 1230 Fall 2015
Turbidity Project
Turbidity Tube vs Spectrophotometer

2. Devise a method to measure the turbidity of an unknown sample and a
sample of pond water.
Response:
We chose to experiment with two methods to compare results.
Method I: Low tech
Method II: High tech
Problem:

3. Constructed of readily available
materials.
Calibrated using McFarland
standard solutions from 0.5 to 6.0.
Tabletop version used a 100 mL glass
graduated cylinder and paper secchi
disk, pushed up to exterior bottom.
Method I: Turbidity Tube

4. Jasco V-630 set at 660nm.
Recorded absorbance of samples of McFarland standard solutions
ranging from 0.5 to 6.0
Method II: Spectrophotometer

5. Turbidity Tube Spectrophotometer
• Inexpensive Expensive
• Portable Stable location
• Man-powered Requires power source
• Large sample needed Smaller sample size
• Accuracy and precision Possible interference
dependent on observer’s to results if sample
eyesight and contains large
interpretation particles
Comparison

6. Results
6
5
4
3
2
1
0
1
2
3
4
5
6
7
0 10 20 30 40 50 60
McFarlandStandardUnits
mL of Sample
Turbidity Tube Calibration
McFarland Standard Units
Linear (McFarland Standard Units)

7. Results
0.5
1
2
3
4
5
6
0
1
2
3
4
5
6
7
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
McFarlandUnits
Absorbance at 660nm
Spectrophotometer Calibration
McFarland Standard Units Linear (McFarland Standard Units)

8. SAMPLE TYPE TURBIDITY TUBE SPECTROPHOTOMETER
UNKNOWN 4.4 4.1
JALPA’S POND WATER < 0.5 <0.5
KALA’S POND WATER < 0.5 <0.5
Results (in McFarland Units)

9. •Expense
•Portability
•Level of accuracy
•Amount of turbidity
Conclusion

10. • The Turbidity Tube: Simple and Accurate Measurement of Turbidity in the
Field; Elizabeth Myre & Ryan Shaw, April 2006
• http://cas.umn.edu/assets/pdf/Turbidity%20Tube.pdf
Chromaticity and Turbidity Quantitative Measurement using UV/Vis
Spectrophotometer
• http://jasco-europe.businesscatalyst.com/assets/uv-0014-e.pdf
• https://water.usgs.gov/owq/FieldManual/Chapter6/Section6.7_v2.1.pdf
• https://en.wikipedia.org/wiki/McFarland_standards
• https://en.wikipedia.org/wiki/Secchi_disk
• http://bcrc.bio.umass.edu/intro/manual/index.php/Gene_Regulation_II
References