Turbidity Tube

Turbidity tubes are used when measuring the turbidity of streams.Below are the steps involved when sampling in the field.

 

Steps

Illustration

Dip tube into the water at your sampling site and fill to the top. Be care to sample flowing water and not the stream bottom. Do not stand upstream from the area you are sampling.

Take the reading in an even light source.

Look through the tube toward the target disk on bottom

  • If the disk is visible, record the water level in centimeters

If the disk is not visible, slowly release water from the valve until the disk becomes visible and then stop the valve.

If it takes awhile to do this and sediment covers the disk then cover your hand over the top and shake the tube to re-suspend any sediment

Once the disk is barely visible, record the water level in cm on your datasheet.

You can then use this table to convert to NTUs.