GE MOA 280i, Руководство по эксплуатации и обслуживанию

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GE Analytical Instruments ©2006
11-5
DLM 14291 Rev. A
Figure 11-1: Connections for Hot and Cold Water for
Nitrate Reduction.
•
When tightening the fittings, hold the union in-line with the glass. If torque is
applied to the union or the union is misaligned, the end of the glass may break.
WARNING:
DO NOT USE WRENCHES TO TIGHTEN THE FITTINGS.
OVERTIGHTENING THE NUT AND FERRULES WILL BREAK THE GLASS!
For nitrate measurements, repeat this procedure to attach the Bubbler line to the
outlet of the purge vessel to the top inlet of the NaOH trap.
To prevent liquid from entering the chemiluminescence reaction cell, a
polypropylene filter disk (IFD) is installed on the outlet of the purge system. One
side of the IFD has two ports, a center port for the gas inlet and a side port to
permit removal of liquid from the filter. The side with two ports faces the purge
vessel. Install the 1/8" Teflon line with the IFD filter to the side port outlet of the
NaOH trap for nitrate, or the outlet of the purge vessel for nitrite and tighten the
nut fingertight.
Connect the 1/8" Teflon tubing from the outlet of the IFD to the inlet of the frit
restrictor on the Sample Inlet of the NOA and tighten fingertight.
The purge vessel requires an inert gas supply (helium, nitrogen, or argon) from a
gas cylinder. The cylinder must be equipped with a two-stage regulator, a shutoff
valve, and an adapter for connection of a 1/8" Swagelok nut. A 1/4" female NPT to
1/8" Swagelok union is provided with the analyzer and permits connection to most
shutoff valves. Wrap Teflon tape on the outlet of the shutoff valve to prevent
leaks on the NPT connection.
Open the main valve on the gas cylinder and adjust the regulator to give 1-2 psi on
the outlet of the regulator. Do not open the shutoff valve. The procedures for
adjusting the gas flow into the purge vessel are in Chapters 12 – 14.
For nitrate measurements, a cold water supply is connected to the barbed fittings
on the condenser of the purge vessel and a hot water supply is connected to the
barbed fittings on the heating jacket of the purge vessel (Figure 11-3).