PerkinElmer OilExpress 4, User Manual

Page: 76 / 152

76 . OilExpress 4 System User's Guide
Defining the Sampling Heights
You can define the system options for sampling heights on the Autosampler Setup dialog:
Ø
Select
Autosampler
from the Instrument sub-menu of the Setup menu.
The Autosampler Setup dialog is displayed (Figure 45).
Figure 45 Autosampler Setup dialog with Use Fixed Heights selected
If you have the optional Ultrasonic Liquid Level Sensor Bar installed, the option
Use
Ultrasonic Height Sensing
will be selected by default, and the OilExpress 4 software will
determine the appropriate height from which to aspirate each sample. The minimum level for
samples depends on your sample container. Refer to
Ultrasonic Liquid Level Sensor Bar
(Optional)
on page 54 for more information.
NOTE: If you have the Ultrasonic Liquid Level Sensor option, but want to enter your own
sampling heights for a batch, you can select
Use Fixed Heights
.
If you do not have the optional Ultrasonic Liquid Level Sensor Bar, then
Use Fixed Heights
will be selected by default and you must define the height of your samples to ensure that
they are aspirated correctly.
The fixed height is defined as the height of the sample measured from the bottom of the
sample holder (not the deck). The minimum fixed height you can enter depends on your
sample container type. When sampling, OilExpress 4 software will calculate a suitable
distance from the height entered to lower the tip into the sample, depending on your
sampling container. This height is optimized to ensure that the sample is aspirated, while
minimizing the depth to which the disposable tip enters the sample fluid. This is to prevent
contamination of your samples by drips from sample collected on the outside of the tip.
You can set the sample heights for
Batch Sample (mm)
and
Control Sample (mm)
. The
Control Sample height enables you to routinely use a lower sampling height for certified
sample materials that are likely to be available in smaller volumes only.