Specifications

Heated Flame Ionization Detector Analyzer Module

Rosemount Analytical NGA 2000

748414-A

August 1999

STARTUP AND OPERATION

4. Enable Calibration Adjustment Limits in the Calibration Parameters menu.

NOTE

If the range selections straddle 725 ppm, CH

, the zero and span calibration for each

range must be done separately.

3.5 ROUTINE OPERATION

After case, oven, and sample temperature stabilization, calibration, and binding, proceed as

follows:

Supply heated sample gas to SAMPLE INLET. Adjust external flow controller or throttle

valve so that the sample inlet pressure is between 5 and 9 psig, 7 psig nominal. The

reading on the SAMPLE pressure gauge and sample and oven temperatures should be the

same as that used during adjustment of the zero and span calibration gas control.

Adjust the Range Number setting. The Analyzer Module will now automatically and

continuously output the measured hydrocarbon content of the sample. Output is in terms of

the particular hydrocarbon present in the span gas. Note that readings obtained during

operation depend on the concentration of total hydrocarbons in the sample.

If maximum sensitivity is required from the HFID Analyzer Module, use an optimum

combination of settings on the FUEL, and AIR pressure regulators. Settings must be

determined experimentally, but the curves in Figures 3-1 and 3-2 may be used as guides.

The Analyzer Module will not allow the user to increase the upper limit of a range beyond

the "maximum range" software setting. To change the "maximum range" value, select the

following from the Main Menu: Technical Configuration Menu, Service Menus,

Manufacturing Data, and Analyzer Module Data. Select Maximum Range, and use the

arrow keys to scroll the indicated value. The same applies for Minimum Range settings.

During shutdown, always turn off fuel gas first, then the air and sample gases. The flame

can also be turned off by setting Ignition System Enable to "Off" in the Light Flame menu

(under Basic Controls). Subsequently, remember to set Ignition System Enable to "On"

before attempting to ignite the flame.

After initial startup, or startup following a prolonged shutdown, the Analyzer Module requires

about one day's continuous operation to stabilize. For several days afterwards, calibrate

daily. The frequency of subsequent calibrations can be reduced as experience dictates,

consistent with the accuracy requirements of the particular application.