The calibration strategy using time-integrated samplers and rainfall events are complementary to each other and enable a correct calibration of turbidimeters and calibration tests regarding the effect of interfering factors (size, color and mineralogy).
Turbidimeter calibration with samples of suspended sediment representing the location is important because the spectral responses obtained by turbidity sensors have no universal connection with the SSC (Mylvaganam & Jakobsen, 2001).
The same material that is transported by the flow must be used for the turbidimeter calibration, and the samples obtained must have the same amplitude of the SSC that may occur in the flow, to avoid the extrapolation of the calibration curve.
Development of smaller, cheaper and easier to use turbidimeters will continue.
In this article it was shown how an integrated circuit of amplified photodiode might speed up development of turbidimeter. An inexpensive transducer which is also easy to reproduce is result of this research.
Portable turbidimeters are furnished by ELE Int'l./Soiltest Products Div.; Hach Co.; Kahl Scientific Instrument Corp.
A mechanical stirrer and a turbidimeter are also desirable.
Until recently, turbidimeters were the sole measurement method used to maintain these standards.
Louisville Water experiments show that turbidimeters provide good accuracy above 1.0 Ntu.
It is important that this equipment be calibrated--after a year or so of operation the turbidimeter
's light bulb can have "aged," producing light wavelengths that are different from those specified.
are furnished by Engineered Systems & Designs; Hach Co.; Kahl Scientific Instrument Corp.; Milton Roy Co., Analytical Prod.