HACH LANGE 9185sc User Manual

HACH LANGE 9185sc User Manual Manual pdf 12 page image

10Installation3.1.2 General Installation Considerations• Place the analyzer in an accessible location.• Keep the sample tubing as short as possible to minimize lag time.• Do not place the probe next to a heat source.• Ensure that there is no air intrusion into the sample supply line.• Sample pressure must be sufficient to ensure a continuous supply to the probe. Aminimum pressure of approximately 0.1–2 bar (1.4–28 psi) is sufficient to provide thecorrect flow rate. A stable flow rate of 200–250 mL/min is critical. Erratic flow rates willcreate erratic measurements.3.2 Choosing the Sample Line LocationNote: Erratic readings will occur if a sample is drawn from a location that is too close to points ofchemical additions to the process stream, if mixing is inadequate, or if the chemical reaction isincomplete.Selecting a good, representative sampling point is important for optimum instrumentperformance (Figure 4). The sample analyzed must be representative of the condition ofthe entire system.Install sample line taps into the side of larger process pipes to minimize the chance ofingesting sediment from the pipe line bottom or air bubbles from the top. A tap projectinginto the horizontal center of the pipe is ideal.Figure 4 Sample Line Location in the Process Stream3.3 Connecting the Sample StreamSample inlet and drain connections are made on the Analyzer Flow Cell. Refer toSpecifications on page 3 for flow rates.The sample inlet requires 6.3 mm (¼ in.) OD tubing. The connections are made with aquick connect fitting. Use the 6.3 mm (¼ in.) supplied tubing adapter in the electrode kit.Cut all tubing so the ends are squarely cut and not angled.1. Push the tubing into the influent of the flow analyzer (Figure 5).2. Push the supplied drain tubing onto the nipple beside the influent.3. Ensure there are no bends in the tubing to prevent back pressure.PoorSediment (Typical)Air (Typical)Poor Good Best