Instruction manual

NGA 2000 HFID
Instruction Manual
HAS64E-IM-HW
September 2008
2 - 2 Installation Emerson Process Management GmbH & Co.OHG
2-3 LOCATION
Install the Analyzer Module in a clean, weather-proofed,
non-hazardous, vibration-free location free from extreme
temperature variations. For best results, install the Ana-
lyzer Module near the sample stream to minimize sample
transport time.
Operating ambient temperature is 15 °C to 35 °C (59 °F
to 95 °F), limited to temperature changes of less than
10 K/hr. Acceptable dew point range is less than 95 %
relative humidity, but not in excess of 45 °C (113 °F) wet
bulb temperature.
The cylinders of fuel, air, and calibration gas(es) and the
source of purge and regulated air should be located in
an area of relatively constant ambient temperature.
2-4 GASES
a. Overview
During normal operation, the Analyzer Module requires
fuel and air to maintain the burner flame as well as suit-
able standard gases for calibration and instrument air for
purge requirements. In addition, instrument air for regu-
lated air in is required to control the sample pressure at
the sample capillary. Criteria for selection of these gases
follow in Section 2-4c.
After initial startup or after startup following a prolonged
shutdown, the analyzer may display baseline drift for a
considerable period of time, particularly on the most sen-
sitive range. Commonly, the drift is caused by small
amounts of hydrocarbons in the inner walls of the tubing
in both the internal flow system and the external gas sup-
ply system. Drift results from any factor influencing the
equilibrium of these absorbed hydrocarbons, such as
temperature or pressure.
Note that this type of drift occurs only when the flame is
burning. If drift occurs when the flame is extinguished,
the electronic circuitry is at fault. To minimze drift, use
clean fuel and air, keep the analyzer clean, and locate
the gas cylinders in an area of relatively constant ambi-
ent temperature.
The cylinders supplying all gases each should be
equipped with a clean, hydrocarbon free, two stage regu-
lator and a shutoff valve.
All new external gas tubing (except for PURGE IN/OUT
and SAMPLE BYPASS) is strongly recommended, pref-
erably precleaned, stainless steel, gas chromatograph
grade tubing. Thoroughly clean before use (if a hydro-
carbon based cleaning solvent such as acetone is used,
purge tubing with dry nitrogen or helium for several min-
utes before using).
Gas line connections are compression fittings. Do not
use pipe thread tape.
Since the oxidation of hydrogen is accompanied by the
formation of water vapor, the Exhaust tubing always
should be slanted downward at least 6 degrees from
horizontal. Otherwise, water may accumulate in the line,
causing back pressure and noisy readings, or may back
up in the line and flood the burner. Depending on the
percent of vapor in the sample, the sample bypass out
connection may be required.
If the sample is toxic or noxious, or is to be reclaimed,
connect the Bypass outlet to a suitable disposal system.
Do not use any device that may cause back pressure in
the line.
Purge air and burner air should be supplied from sepa-
rate sources.
WARNING
INSTALLATION RESTRICTIONS
For safety, the Analyzer Module should be installed
in a non-confined, ventilated space. Do not block
any of the rear panel outlets as they are part of the
safety system.