Gow-Mac 580 series, Operating Manual

Page: 26 / 68

GOW-MAC Instrument Co. 26
7. SIGNAL AMPLIFIER (Option 407): Amplifi es the analog millivolt detector output signal by a
factor of 10.
8. COLUMN HEATER & FAN SWITCH: Controls the operation of the column oven heater and
fan. The heater will operate only when the switch is in the “Column Heater & Fan” position.
This is the normal operating position. For rapid cooling of the oven, the heater may be turned
off and the fan operated alone by placing the switch in the “FAN ONLY” position.
9. DETECTOR CURRENT CONTROL: Determines the sensitivity of the instrument. The higher
the current, the more sensitive the instrument becomes. Charts 5-1 thru 5-4 illustrate the
maximum current for each specifi c cell temperature. THIS SHOULD NOT BE EXCEEDED!
However, for longer fi lament life and a stable baseline, lower fi lament temperatures are
recommended. Reference recommended starting bridge settings (Section 5).
NOTE
)
DUAL CARRIER TCDs: Controls to set the TCD temperature and
bridge current are as described above.
Special attention is required when setting the TCD temperature
and bridge current on a dual carrier detector. Helium is normally
one carrier gas while either nitrogen or argon is the other. To
determine the operating limits of the TCD current and temperature,
refer to Charts 5-4 and 5-5 in Section 5. Go to the particular chart
for your fi lament type, then select the current and temperature to
stay below and to the left of the curve for the appropriate carrier
gas (N
2
or Ar).
10. ATTENUATOR: Twelve step, 1 to 1024 plus infi nity, in multiples of 2. Attenuates the output of
the bridge current. A setting of “1” represents maximum sensitivity.
11. ZERO CONTROL: Adjusts the detector output level for zeroing the baseline on the recorder.
(Recorder should be zeroed fi rst, with short input).
12. METERING VALVES: Adjusts the fl ow of detector the carrier gas to the detector.
13. INJECTION PORTS “A” & “B”
14. OVEN LID
15. EXIT PORTS “A” & “B”