What is the accepted method for measuring turbidity in water?

The accepted method for measuring turbidity in water is the nephelometric method. This technique utilizes a nephelometer, which measures the amount of light scattered at a specific angle from a beam of light as it passes through a water sample. Turbidity is a measure of the cloudiness or haziness in water, caused by particles that scatter light.

In the nephelometric method, the intensity of the scattered light is proportional to the concentration of suspended particles in the sample, providing a quantifiable measure of turbidity. This method is widely recognized for its accuracy and reliability, making it the standard for turbidity measurement in water quality assessment.

Other methods, such as colorimetric analysis, gravimetric analysis, and visual comparison, have limitations that affect their suitability for accurately measuring turbidity. Colorimetric analysis often targets specific substances or color-related properties rather than turbidity. Gravimetric analysis involves weighing particles, which can be time-consuming and does not directly measure turbidity. Visual comparison relies on subjective interpretation and does not provide precise or repeatable measurements, making it less effective than the nephelometric method.