Gow-Mac 400 Series, Operating Manual

Page: 25 / 64

25 Series 400 / 402 Gas Chromatograph Operating Manual GOW-MAC Instrument Co.
May 2017, Rev. 7
12.
ATTENUATOR
: Twelve step to 1024 plus infi nity, in multiples of 2. Increases or decreases the
size of the peaks obtained by attenuating the output of the bridge current. A setting of "1"
indicates maximum sensitivity.
13.
DETECTOR CURRENT CONTROL:
determines the sensitivity of the instrument. The higher
the current, the more sensitive the instrument becomes. Chart 4-1 illustrates the maximum
current for specifi c cell temperature.
THE MAXIMUM CURRENT SHOULD NOT BE
EXCEEDED! For longer fi lament life and a stable baseline, lower fi lament temperatures are
recommended. Recommended starting bridge setting is 100 mA for helium carrier gas.
14.
FLOW ADJUSTMENT "B"
15.
INJECTION PORT "B"
16.
COLUMN OVEN LID
17.
EXIT PORTS "A" & "B"
18.
COLUMNS
The oven is designed to accept twelve (12) feet of 1/4" tubing. Correspondingly longer lengths
of 1/8" tubing can be wound on a mandrel of 4" o.d. Columns of 1/8" o.d. with 1/4" ends can
be ordered from GOW-MAC. Figure 4-2 illustrates columns "A" & "B". An appropriate column
or bypass must be installed in both "A" and "B" sides or damage will result to the detector.
Column A Column B
Left Side Right Side
Figure 4-2
Columns
4.2 Initial Test Warmup
The chromatographer should be familiar with the techniques of chromatography, the function
of all controls, the operation of the recording device, and the characteristics of the columns
used prior to running samples.