Determining the Volume of Water Sampled
To compute the volume of water sampled as you towed your net through the water, you need to know the total distance towed and the diameter of the opening of the net.
r = radius of net opening in meters
PLANKTON NET
Volume of water sampled =
p (radius)2 of x (total distance in cubic meters (M3) net opening in meters towed) in meters. (p = pi or 22/7)------------------------------------------------------------------------
Example:
Total distance of net tow 10 M
Diameter of Net in Meters 0.24 M
Radius of Net in Meters = diameter / 2 = 0.12 M
Volume of Water sampled in M3 =
p r2 towed distance in Meters= (22/7) (.12m)2 x (10m)
= (22/7) (.0144) x (10m)
= 0.4526 M3
--------------------------------------------------------------------------
1. Now calculate the volume you sampled:
2. Record the volume on your data sheet.
Introduction - Volume of Sample - Numbers in Sample 1