Hach FT660 sc Manuel D'utilisation De Base page 11

Plumbing
Sample line considerations
Select a good, representative sampling point for optimum instrument performance. The sample
analyzed must be representative of the conditon of the entire system.
To minimize erratic readings:
• Draw samples from locations that are sufficiently distant from points of chemical additions to the
process stream
• Make sure samples are sufficiently mixed
• Make sure all chemical reactions are complete
Connect the sample stream
Connect sample inlet and drain lines to the fittings on the body of the instrument
on page 7). Sample inlet and drain tubing are supplied by the customer. Refer to
on page 3 for tubing requirements.
Install the sample line(s) into a larger process pipe to minimize interference from air bubbles or
pipeline bottom sediment. A sample line going into the center of a process pipe is best.
Figure 6 shows examples of good and bad methods of installing a sample line into a process pipe.
Notes:
• Keep the sample inlet and drain tubing as short as possible to minimize lag time of the sample
flow.
• Control the flow rate into the instrument with a flow restriction device on the sample line. Refer to
Specifications on page 3 for flow rate specifications.
Note: Flow rates greater than 750 mL/minute will cause the instrument to overflow into the drain, decrease the
performance of the bubble trap and cause incorrect readings.
Figure 6 Sampling methods
1 Air
Operation
Using the sc controller
Before using the instrument with an sc controller become familiar with the operating mode of the sc
controller. Refer to the sc controller user manual and learn how to use and navigate the menu
functions.
2 Sample flow
(Figure 1
Specifications
English 11