Dark Current Test - Agilent Technologies 1260 Infinity User Manual

8
Test Functions

Dark Current Test

The dark-current test measures the leakage current from the sample and
reference circuits. The test is used to check for defective sample or reference
diodes or ADC circuits which may cause non-linearity or excessive baseline
noise. During the test, the lamp is switched off. Next, the leakage current from
both diodes is measured.
When to do the Test
• if the detector signal is noisy.
Interpreting the Results
The output signal of the ADC noise corresponds to AD counts with 1 V or 0.1 V
full scale setting. The ADC noise must be taken over a time of 10 minutes for
the results to be accepted.
Average counts should be less than 7900 counts
Dark Current Test Failed
Probable Causes
1 Defective sample or reference diode.
2 Defective sample or reference VWA board.
3 Defective VWM board.
124
Suggested Actions
Exchange optical unit.
Exchange optical unit.
Exchange the VWM board.
Agilent 1260 Infinity Variable Wavelength Detector User Manual