Hach APA 6000, Installation Manual

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Connect the sample stream
Install the sample line into a larger process pipe to minimize interference
from air bubbles or pipeline bottom sediment. A sample line that goes
into the center of a process pipe is best.
Figure 18 shows examples of good and bad methods of sample line
installation into a process pipe.
Keep the sample line as short as possible to decrease analysis delay.
Sediment can collect in long sample lines.
Figure 18 Sampling methods
1 Air 2 Sample flow
Sample considerations
For wastewater applications or other samples that contain a large
amount of solids, use a 40-mesh Y-strainer to remove large solids alone
or with the optional micro filter system. Refer to
Replacement parts and
accessories in the maintenance manual.
For highly aerated samples, a sample heater is recommended.
Increasing the temperature of the samples removes some of the excess
air and stabilizes the analyzer readings.
Sample line and valve cleanup
C A U T I O N
Chemical exposure hazard. Obey laboratory safety procedures and
wear all of the personal protective equipment appropriate to the
chemicals that are handled. Refer to the current safety data sheets
(MSDS/SDS) for safety protocols.
New tubing, valves and other sample conditioning equipment may be
contaminated with silicate-based substances (oils, dust). These may
contribute to slightly high readings until they are cleaned.
1. Flush the sample line with sample for one to two hours.
2. For an expedient procedure, inject one to four liters of a dilute caustic
solution such as 1N (5%) sodium hydroxide solution into the front
end of the sample line. Force the solution through the analyzer to
clean sample system components.
Attach an air purge line (optional)
If the analyzer is installed in an environment with high humidity or caustic
vapors, attach an air purge line to the analyzer. Refer to
Specifications
on page 3 for air purge specifications.
Note: The case drain is the vent for the air purge.
1. Remove the plug from the air purge fitting. Refer to Figure 2
on page 7.
2. Push 0.25-in. OD x 0.040-in. ID poly tubing into the air purge quick-
connect fitting until two distinct stops are felt.
Note: If not fully installed, the tubing will disconnect from the air purge fitting
when air pressure is applied.
Preparation for use
The physical installation is now complete. Refer to the operations
manual to set up the analyzer for the first use.
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