Agilent Technologies 1220 Infinity II LC User Manual page 190

9
Test Functions and Calibration
Diode Array Detector (DAD)
D/A Converter (DAC) Test
The detector provides analog output of chromatographic signals for use with
integrators, chart recorders or data systems. The analog signal is converted
from the digital format by the digital-analog-converter (DAC).
The DAC test is used to verify correct operation of the digital-analog-converter
by applying a digital test signal to the DAC.
The DAC outputs an analog signal of approximately 50 mV (if the zero offset of
the analog output is set to the default value of 5 %) which can be plotted on an
integrator. A continuous square wave with an amplitude of 10 μV and a
frequency of approximately 1 cycle/24 seconds is applied to the signal.
The amplitude of the square wave and the peak-to-peak noise are used to
evaluate the DAC test.
When If the analog detector signal is noisy or missing.
Preparations Lamp must be on for at least 10 minutes. Connect integrator, chart recorder or data system to the
detector analog output.
Running the test with Agilent LabAdvisor
1 Run the D/A Converter (DAC) Test (for further information see Online-Help of
190
user interface).
Figure 61 D/A Converter (DAC) Test – Results
1220 Infinity II LC System User Manual