Emerson NGA2000 TO2 Benutzerhandbuch

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Instruction Manual 
748374-F 
March 2003 
4-2          Maintenance and Troubleshooting 
Rosemount Analytical Inc.    A Division of Emerson Process Management 
Model NGA2000 TO2
 
a. Water 
Addition 
To add water: 
1.  Remove the top  cover of the analyzer 
module. 
2.  Unscrew the black sensor cover. 
3.  Slide the cover back just enough to al-
low the neck of the fill bottle to fit into 
the sensor reservoir. 
4.  Add distilled or deionized water using 
the fill bottle provided with the analyzer 
module.  Fill to approximately midway 
between the min and max level indica-
tors on the sensor label.  Be careful not 
to spill water, splash electrolyte or over-
fill sensor. 
5.  Replace the sensor cover securely. 
6.  Replace the top cover of the analyzer 
module. 
If the electrolyte alarm is activated but the 
sensor shows sufficient electrolyte, the elec-
trolyte may have been contaminated by 
substances present in the sample which are 
chemically incompatible with the sensor or 
electrolyte.  If this should occur, the electro-
lyte must be drained and replaced with 
fresh electrolyte. 
Refer to Section 4-3 below for the proper 
procedure for replacing electrolyte. 
Several other components may require re-
placement. These are discussed in the fol-
lowing sections. 
4-2 FUSES 
Remove power to the Analyzer Module prior to 
fuse replacement.  To replace the Power Fuse, 
locate the fuse cover on the front panel of the 
Analyzer Module, as shown partially in Figure 
2-3 on page 2-4.  Push and turn the fuseholder 
cover 1/4 turn counterclockwise.  Remove and 
replace the fuse as required.  There are no 
other fuses in the Analyzer Module. 
4-3 ELECTROLYTE REPLACEMENT 
Before replacing the electrolyte, be sure to turn 
off and disconnect all gas connections to the 
analyzer module.  Turn off or disconnect the 
power to the analyzer module. 
To replace the Sensor electrolyte, remove the 
Analyzer Module from its mounting location and 
place on a sturdy work surface.  Be careful not 
to tilt the module from its horizontal position as 
the Sensor contains liquid that can spill.  Re-
move the cover of the Analyzer Module and lo-
cate the 5 mounting screws that hold the Sensor 
Assembly onto the Analyzer Module chassis 
(see Figure 4-1 on page 4-1).  Remove the 5 
screws and retain. Do not lose the screws - they 
have metric threads. 
Disconnect the Sensor signal connector (J5) 
and the Flow Sensor connector (J6)  from the 
power board.   Remove the complete Sensor 
Assembly from the Analyzer Module.  Remove 
the black sensor cover and invert the Sensor 
Assembly over a suitable receptacle.  Flush the 
Sensor twice with deionized water.  Dispose of 
the discarded electrolyte and rinse water in ac-
cordance with National, Federal, State and Lo-
cal regulations. (See MSDS in the rear of this 
manual.) 
Refill the Sensor with electrolyte as instructed in 
Section 2-2a on page 2-1.  Reinstall the Sensor 
Assembly and reconnect J5 and J6 to the power 
board. 
4-4 SENSOR REPLACEMENT 
If the Sensor cannot be regenerated by the ad-
dition of water or the replacement of electrolyte, 
or if the Sensor shows signs of leakage, it may 
be necessary to replace the Sensor.  To replace 
the Sensor, remove the Sensor Assembly and 
remove the electrolyte as described in Section 
4-3 above.  Reinstall the black sensor cover to 
catch any residual electrolyte.  Invert the Sensor 
Assembly and locate the four (4) mounting 
screws which hold the Sensor to the Sensor As-
sembly mounting plate.  Remove and retain the 
four screws.