Thermo Scientific ISQ EC, Operating Manual

Page: 65 / 232

5

Installation
ISQ EC and ISQ EM Mass Spectrometer Operating Manual Page 65
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Each instrument requires up to 30 L/min of nitrogen

In standby, the instrument consumes ~15 L/min of nitrogen.
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¼ in. OD Teflon tubing should be used to connect to each
instrument. 760 cm is provided in the installation kit.
NOTICE—Do not use 6 mm tubing. This can damage the fittings. Use
only ¼ in. OD Teflon tubing.

If connecting multiple instruments to one nitrogen line, ensure the
minimum pressure is delivered to each instrument when all are
consuming the maximum amount of gas.

The system should be placed close to the nitrogen gas source since gas
pressure decreases as the length of tubing increases.

Options for delivering nitrogen are (in order of convenience):

A nitrogen generator: These are available in larger units that may be
remotely located or as point-of-use systems. Work with the specific
vendor in order to determine output purity via an oxygen sensor.
Point-of-use systems require compressor maintenance every 3,000
hrs.

Facility size Dewar: These are large globes located outside a facility.
They are filled as needed.

Portable Dewar: These are roll around Dewars. Be sure to get one
capable of outputting 100 psig. The 35 and 80 psig models do not
provide sufficient gas pressure. There can be problems with them
not boiling off nitrogen fast enough at high flow rates. Plan to
change Dewars more often than you think, especially when not
using much gas. At low, or no, consumption, the Dewar must still
vent off nitrogen during the day to prevent it from going too high in
pressure. This boil off rate is a function of the ambient
temperature. In our experience, a Dewar will go empty in 2-3 weeks
even if not used.