Hach Lange 2100AN, Инструкция по эксплуатации инструмента

Страница: 53 / 108

SECTION 5,
continued
53
5.2.1.2 Assembling the Flow Cell
Verify the O-rings have been installed in the top and bottom end caps; then screw
the caps on to the glass sample cell. Tighten the caps enough to ensure a water-
tight seal, but do not over tighten.
5.2.1.3 Connecting Inlet and Outlet Tubing
Note: Use the tubing supplied with
the kit (or its equivalent). Tubing
lengths are approximate. Avoid
using excess tubing because it
causes air locking, and delays
measurement response time.
1. Cut a 53-cm (21") piece of clear,
1
/
8
" I.D. Tygon tubing, and install it between
the inlet reservoir and cell inlet.
2. Cut two 23-cm (9
"
) pieces of clear,
1
/
8
" I.D. Tygon tubing, and install them
between the top and bottom Flow Cell drain fittings and the “Y” connector.
3. Cut a 2.5-cm (1") piece of clear,
1
/
8
" I.D. Tygon tubing, and install it between
the “Y” connector and the Collection Drain Assembly.
4. Cut a 50-cm (20") length of clear,
3
/
8
" I.D. Tygon tubing for the drain line.
Connect one end to the drain barb on the Collection Drain Assembly, and run
the other end to a suitable drain.
The discharge end of the drain tube must be unrestricted and lower than the
instrument for proper drain flow and prevention of air locking. Locate the
instrument as close to the drain as is practical using the shortest length of drain
tubing possible.
The kit is supplied with 152 cm (5') of 3 /
8
" tubing. The system will not drain
properly if this length is exceeded. If the entire length is used, the end of the drain
tubing must discharge at a point at least 46 cm (15") below the center line of the
instrument to ensure proper flow.
5.2.1.4 Using the Manual Flow-Cell Kit
Note: Assemble the Flow Cell,
tubing and stand. Fill the system
with water to ensure all connections
are water tight before inserting the
Flow Cell into the sample
compartment of the instrument.
Inspect the system for leaks. Also,
make sure the cell is clean, and no
air bubbles are present. Air bubbles
tend to collect in areas that are not
cleaned thoroughly.
Thoroughly clean the flow cell (refer to Section 5.2.5 on page 63). Apply a thin
coat of silicone oil to the outside of the flow cell.
Install the Flow Cell in the sample compartment and press the inlet and outlet
tubes into the slots provided on the instrument's top enclosure (see Figure 9).
Cover the cell with the Flow-Cell Light Cover.
The Flow-Cell Light Cover must be installed at all times when the Flow Cell is in
use. The instrument's cell cover does not close when the Flow Cell is installed.
Flow rate through the Flow Cell is controlled by adjusting the height of the
Collection Drain Assembly on the Support Rod. Position the bottom of the
Collection Drain Assembly a minimum of 7.5 cm (3") above the support stand
base. Raise the Collection Drain Assembly on the Support Rod to decrease the
rate of flow. Lower the Collection Drain Assembly until it rests against the
support base to purge the Flow Cell of sample.
Carefully add sample to the Inlet Reservoir to minimize entrapment of air bubbles
in the sample. Air bubbles create a false positive interference in turbidity
measurement. Always slowly pour sample down the inside edge of the reservoir.