LaMotte DO 6 Dissolved Oxygen Meter - Manual (Page 52)

14.1.5 Applications
Oxygen is essential for fish, invertebrate, plant, and aerobic bacteria
respiration. DO levels below 3 ppm are stressful to most aquatic organisms.
Levels below 2 or 1 ppm will not support fish. Fish growth and activity usually
require 5 to 6 ppm of DO, an important consideration for aquaculture industry.
Low DO indicates a demand on the oxygen of the system. Natural organic
material such as leaves accumulate in the stream and create an oxygen demand
as it is decomposed. Organic materials from human activities also create an
oxygen demand in the system. Micro-organisms consume oxygen as they
decompose sewage, urban and agricultural run-off, and discharge from
food-processing plants, meat-packing plants and diaries. There is an optimum
DO level for this process and if DO level falls too low, the micro-organisms die
and the decomposition ceases. If DO level is too high, more power is used
than necessary for aeration and the process becomes costly.
In boiler water application, presence of oxygen in the water will increase
corrosion and helps build up boiler scale that inhibits heat transfer. In such
instance it is critical to keep DO concentration to a minimum.
Some pollutants such as acid mine drainage produce direct chemical demands
on oxygen in the water. DO is consumed in the oxidation-reduction reactions
of introduced chemical compounds such as nitrate (NO
31-
) and ammonia
(NH
41+
), sulfate (SO
42-
), and sulfite (SO
32-
) and ferrous (Fe
2+
) and ferric (Fe
3+
)
ions.
These are important consideration for water and wastewater treatment
industry.
15 LIMITED WARRANTY
LaMotte Company warrants this instrument to be free of defects in parts and
workmanship for 3 years from the date of shipmen and this probe to be free of
defects in parts and workmanship for 6 months from the date of shipment. If it
should become necessary to return the instrument for service during or beyond
the warranty period, contact our Technical Service Department at
1-800-344-3100 for a return authorization number or visit www.lamotte.com
for troubleshooting help. The sender is responsible for shipping charges,
freight, insurance and proper packaging to prevent damage in transit. This
warranty does not apply to defects resulting from action of the user such as
misuse, improper wiring, operation outside of specification, improper
maintenance or repair, or unauthorized modification. LaMotte Company
specifically disclaims any implied warranties or merchantability or fitness for a
specific purpose and will not be liable for any direct, indirect, incidental or
consequential damages. LaMotte Company’s total liability is limited to repair
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