Emerson Process Management NGA2000 HFID 用户手册

748297-E 
June 2003 

3-6     Startup and Operation                                                                Rosemount Analytical Inc.    A Division of Emerson Process Management 

Model NGA2000 HFID

The HFID Analyzer Module safety system will 
not allow ignition or continuous burner func-
tion unless the following conditions are pre-
sent: 

•  The internal purge gas pressure is at 

least 380 hPa - gauge (5.5 psig). (Moni-
tor display message, Purge Gas Pres-
sure in Physical Measurements menu, 
for proper setting.) 

•  Flow rate for purge air in is at least 

16 L/min. and case pressure is greater 
than 0.5 inches of water. (Monitor dis-
play message, Purge Gas (ON) in Mis-
cellaneous Control Parameters menu for 
correct state. Proper sealing hardware 
must be used in order to obtain the re-
quired purge air in flow rate and case 
pressure). 

•  Five case volumes of purge air have 

been achieved and the three above 
conditions are present. The time dura-
tion to achieve a safe system is a mini-
mum of 6 min. The elapsed time can be 
monitored in the Technical Startup Ana-
lyzer menu. (Monitor the Purge Air 
Green LED (ON), Purge Control Status 
(ON), or Purge Air Alarm for indication 
of the state of the safety system.) 

As stated above, proper sealing hardware is 
crucial to the successful operation of the 
safety system. Therefore, a specific torque 
sequence (shown in Figure 3-3 on page 3-8) 
must be followed when the front panel of the 
module is being reinstalled after removal. All 
front and rear panel screws must be installed.