Reader; Capacitive Liquid Level Detection - Lonza PyroTec PRO Hardware User Manual

5.4 Reader

The following microplate reader type is supported and always mounted on the instrument
worktable:
•
The microplate is loaded and unloaded by means of a RoMa arm. For more information
about the microplate reader, refer to the reader's documentation.

5.4.1 Capacitive Liquid Level Detection

How Does it The integrated capacitive liquid level detection (cLLD) measures the capacitance between
Work? the tip and the instrument worktable; i.e. the corresponding carrier. As soon as the tip
touches the liquid surface, the change in capacitance serves to trigger a detection signal.
The conductivity of the liquid and the labware type have influence on the detectability.
The liquid level detection evaluates both the liquid detection signal (when the tip moves
into the sample liquid) and the exit signal (when the tip retracts).
Each channel has an individual liquid detection.
Influencing The application software offers the following adjustments of influencing variables:
Variables
• The sensitivity of the liquid level detection can be adjusted.
• In order to improve the detection, "Double Detection" is used; i.e. the detection is
performed once, then the tip retracts by a short distance and a second detection is
performed. The results are only considered valid if the measured detection levels are
within a specified limit. This is useful, e.g. if there are bubbles on the liquid surface.
Advantages Advantages due to the liquid detection feature:
Minimum submerge depth of the tip
•
• Reduced tip contamination and accordingly less washing effort for tip
PyroTec™ PRO Hardw are User's Manual, V1.2
Tecan® Sunrise™
Liquid level detection
o The first detection run detects the surface of the bubble.
o The bubble bursts at the latest when the tip retracts.
o A second detection run will measure a different detection level.
o The first value is rejected and the detection is repeated
1) The tip moves downwards to detect
liquid.
2) The tip is at detection level.
3) The tip has contact to the liquid sur-
face after detection.
A Tip
B Liquid level
C Sample
D Tube
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RT-MN024-1.2 02/21