PerkinElmer OilExpress 4, User Manual

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Overview of the OilExpress 4 System . 45
Figure 22 The two-port flow cell
The flow cells supplied with the system are fitted with two zinc selenide (ZnSe) windows. These
are separated by a wedged (to minimize unwanted fringing effects) spacer to give a nominal
pathlength of 0.1 mm. You can calibrate the Pathlength Calibration utility in OilExpress 4
software, which using a Quant method to calculate the pathlength. A Quant method is supplied
with your system, but you can configure the test to use your own method.
The pathlength calibration will be performed for the flow cell(s) supplied with your system by
a PerkinElmer Service Representative during the installation. However, you will need to
recalibrate after any flow cell maintenance or refurbishment. Refer to Calibrating the
Pathlength of the Flow cell starting on page 109 for more information.
Liquid Presence Sensor
The liquid presence sensor located on the sample shuttle is used to detect the front of the
sample fluid flowing into the flow cell as the sample is dispensed from the pipet tips. The
time taken from the start of the dispense for the sensor to detect the sample is used to
calculate the time needed to fill the flow cell, and the adaptive cleaning parameters for
cleaning the fluid lines and flow cell after the sample measurement.
When liquid is detected, the LED is lit green (Figure 23). When no sample is detected, the
LED is lit red (Figure 24).
Figure 23 Liquid presence sensor indicating sample detected