Hach-Lange SURFACE SCATTER 7 sc Turbidimeter - Manual (Page 23)

21
Installation
3.5 Connecting hydraulics
Note: When connecting the hydraulics to the bottom of the unit, hold the
¾-in. bulkhead adapters on the inside of the enclosure with the door open.
The sample in, body drain and overflow drain are connected to the
instrument as shown in
Figure 5 on page 13 . The sample inlet port
is fitted with a ¾” NPT female fitting with ¾” ID hose barb adapter
fitting. A ball valve is supplied with the instrument to drain the
turbidimeter body. Hose barb adapter fittings for sample in and both
drain fittings are also supplied.
A Bubble Trap/Head Regulator (Cat. No. 46680-00) is
recommended if the sample cannot be delivered bubble-free to the
analyzer. The device may also be used as to dampen fluctuations in
flow due to pulses from a pump and/or sample pressure.
Using the Bubble Trap/Head Regulator will increase response time
to changes in sample concentration. The increase in response time
may vary from 1–2 minutes at 2 L/min. For fastest response time,
use the highest flow practical for sample conditions. Higher flows
decrease the effectiveness of bubble removal. The need for fast
response time and bubble removal must be balanced for
optimum performance.
Install the Bubble Trap/Head Regulator so the overflow is at least
five inches above the top of the sample unit enclosure (
Figure 12
on page 22 ). However, installation height can vary based on local
sample conditions and flow requirements. See the installation
instructions supplied with the Bubble Trap/Head Regulator for
more information.
Figure 11 Sampling techniques
1 Poor 5 Sediment (typical)
2 Sampling line to sample unit 6 Good
3 Sample flow 7 Best
4 Air (typical)