Thermo Scientific FOCUS GC, Instruction Manual

Page: 181 / 356

Chapter 9
Detector Signal Parameters Thermal Conductivity Detector (TCD)
Instruction Manual 181
Detector Signal Parameters
The detector
SIGNAL
menu contains the parameters that control the detector
signal. In Main Menu move the cursor until
Signal
is selected. Press
ENTER
to
display the
SIGNAL
menu.
1. Manual Offset can be entered only if an autozero has been performed before successfully.
SIGNAL (TCD)
Output (5000)
Offset 25000
Run autozero
Gain x10
Neg polarity? No
Table 9-5. TCD Signal Parameters
Parameter Range Description
SIGNAL
This line is the title bar
Output
1
Not editable This is the actual output signal.
The
Autozero
function forces this value to 1000
corresponding to the zero level of the baseline on a recording
device.
Offset 0 to Variable This is a value in counts that may be subtracted from the
Output
signal to adjust the baseline level. This parameter may
be manually or automatically set using the
Autozero
function.
The range of the suppression is variable and related to the
operating conditions.
Run autozero
This function forces the output signal to 1000 (zeroing). Press
ENTER to zero the detector signal.
Gain
1, 10 This parameter increases the amplifier gain by a factor of 10.
Neg.
polarity?
Yes/No This parameters allows to reverse the polarity of the signal as a
function of the thermal conductivity of the carrier gas.