Hitachi CHROMASTER 5160, Instruction Manual

Page: 348 / 1022

4.2.2
(4) Baseline Measurement in 2-wavelength Measurement
2-wavelength measurement is settable from the CDS.
This measurement cannot be carried out by the detector
alone.
•
Conditions........................ Room temperature constant,
air in flow cell, data sampling
period 800 ms
•
Measuring wavelength..... Wavelength 1; 210 nm,
wavelength 2; 250 nm
•
Specification .................... Noise; 3.5
×
10
-5
AU or less
(when measured at least 1
hour after power-on)
4.2.2 Measurement of Baseline Noise
Detector specifications are to be checked by measuring noise on
the baseline. For this measurement, the following devices
should be prepared.
•
Recorder or Model D-2500 chromato-integrator
•
Vernier caliper (max. measurable length 200 mm or more,
minimum readable value 0.1 mm or less)
NOTE : When the inside of flow cell is wetted with liquid,
baseline noise and drift may increase.
To prevent this, wash the flow cell with an organic
solvent such as methanol, and then conduct
purging adequately using nitrogen gas. While an
organic solvent such as methanol or acetonitrile is
delivered through the cell, the baseline noise and
drift may be reduced.
Conditions
•
Wavelength : 250 nm
•
Time constant (response) : 2 sec
•
Sampling period of chromato-integrator : 400 ms
•
Measurement time : 15 minutes
•
Warm-up : 1 hour
4 - 3