eutech-instruments ecoscan do 6 do meter Manuel D’Utilisation

Instruction Manual 

DO 6 

 
 

63

 

Dissolved Oxygen (DO) refers to the volume of oxygen that is contained in 
water.  There are two main sources of DO in water: from atmosphere and 
photosynthesis.  Waves and tumbling water mix air into the water where oxygen 
readily dissolves until saturation occurs.  Oxygen is also produced by aquatic 
plants and algae as a by-product of photosynthesis.   

The amount of DO that can be held by water depends on 3 factors:  water 
temperature, salinity, and atmospheric pressure. 

1)  Amount of DO increases with decreasing temperature (colder water holds 

more oxygen); 

2)  Amount of DO increases with decreasing salinity (freshwater holds more 

oxygen than saltwater does); 

3)  Amount of DO decreases with decreasing atmospheric pressure (amount 

of DO absorbed in water decreases as altitude increases).