Varian 450-GC, User Manual

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Pulsed Pulsed Flame Flame Photometric Photometric Detector Detector (PFPD) (PFPD) - - Detectors Detectors
Varian, Varian, Inc. Inc. User User Manual Manual 450-GC 450-GC Page: Page: 365 365
Adjust the Gas Flow Rates Adjust the Gas Flow Rates
Tools and equipment needed to complete the following procedure. Tools and equipment needed to complete the following procedure.
Refer to parts and
Refer to parts and supplies supplies ,, on page 412 on page 412 ..
••
Varian Varian Intelligent Intelligent Digital Digital Flowmeter Flowmeter or or Soap flowmeter Soap flowmeter
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Stopwatch Stopwatch
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Flow Flow measuring measuring adapter adapter (1/8"-to (1/8"-to-1/16" -1/16" Swagelok® Swagelok® reducing reducing union) union)
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1/4" 1/4" flat flat blade blade screwdriver screwdriver
For best stability of For best stability of flows, flow flows, flow controll controll ers should have pre ers should have pressure applied ssure applied
to them for at least 24 hours before adjustments are made. A moderate to them for at least 24 hours before adjustments are made. A moderate
flow of gas through the flow controller during this conditioning period is
flow of gas through the flow controller during this conditioning period is
also helpful in stabilizing the flow contr
also helpful in stabilizing the flow contr oller. oller.
1. 1. Turn Turn the the igniter igniter OFF. OFF.
2. 2. Locate Locate the the Air1 Air1 mass flow controller valve (Item 1). Note the current dial mass flow controller valve (Item 1). Note the current dial
setting. Turn setting. Turn Air1 Air1 OFF. OFF.
3. 3. Locate Locate the the Air2 Air2 mass flow controller valve (Item 2). Note the current dial mass flow controller valve (Item 2). Note the current dial
setting. Turn setting. Turn Air2 Air2 OFF. OFF.
4. 4. Locate Locate the the Hydrogen Hydrogen mass flow controller valve (Item 4). Note the current mass flow controller valve (Item 4). Note the current
dial setting. Turn dial setting. Turn Hydrogen Hydrogen OFF. OFF.
5. 5. Install the Install the flow measu flow measuring adap ring adapter (Swagelo ter (Swagelok 1/8" to 1 k 1/8" to 1/16" reduci /16" reducing union ng union))
to the threaded hole in the igniter cap. Connect a 2-3" piece of tube to 1/8" to the threaded hole in the igniter cap. Connect a 2-3" piece of tube to 1/8"
end of the union. Use Teflon thread tape to make the connection to the
end of the union. Use Teflon thread tape to make the connection to the
igniter cap gas tight. Measure and record the column flow
igniter cap gas tight. Measure and record the column flow rate, then turn rate, then turn
the column flow OFF. the column flow OFF.
A Var A Varian ian Int Int ell ellig ig ent ent Dig Dig it it al Fl al Fl ow owmet meter er is is hi hi gh ghly ly rec recom ommen mended ded fo for t r t hi hi s s
procedure. procedure.
Be sure the igniter sea Be sure the igniter seal is l is completely leak tight before attempting to completely leak tight before attempting to
measure flow rates. This seal can loosen due to temperature cycling measure flow rates. This seal can loosen due to temperature cycling
during
during normal operation. T normal operation. This do his do es not affect detector performance, but es not affect detector performance, but
can lea can lead to d to serious errors in serious errors in setting flow setting flow rate rates. Tighten secure s. Tighten securely before ly before
beginning to m beginning to m ea easure flows. sure flows.
6. 6. Adjust Adjust the the Air1 Air1 mass flow controller valve until flow rate is near 17 mL/min. mass flow controller valve until flow rate is near 17 mL/min.
Write down and save the dial Write down and save the dial setting for the setting for the Air1 Air1 mass flow mass flow controller valve. controller valve.
Turn the Turn the Air1 Air1 flow controller Off. flow controller Off.