5 Setting sensor thresholds
Overview for setting sensor thresholds
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BenchCel Microplate Handler User Guide
Overview for setting sensor thresholds
About this topic
You must set the Plate-presence and Orientation thresholds correctly for the specific
type of labware you are using to ensure proper operation. For example, the thresholds
must be accurate to ensure proper upstacking and downstacking of the labware. You
must set the thresholds for the labware type before using the labware in a BenchCel
protocol run.
This topic explains how the plate-orientation senors work and the workflow for setting
the sensor thresholds.
How the plate-orientation sensors work
Four plate-orientation sensors on the inside wall of the stacker head detect the
presence of microplate notches when the microplate is downstacked. Each sensor
contains a light emitter that transmits light, and a receiver that reads the amount of light
reflected by the surface of the microplate.
If the light beam bounces off of a wall that is perpendicular to its path, most of the light
will reflect back. The resulting reading is relatively high. If the light beam bounces off of
a wall that is not perpendicular to the light path, the light will be deflected. The resulting
reading is significantly lower.
Figure
Emitted light path on the notched and unnotched corners of a plate
The amount of light that the sensor receives is displayed in BenchCel Diagnostics on
the Controls page Jog/Teach tab. The microplate corners that have notches should
have much lower readings than the corners that do not have notches. In the following
example, the sensors detect a notch in the upper right and lower left corners of the
microplate.
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Emitted light deflects
at plate notch and
produces low sensor
reading.
Emitted light reflects
back and produces
high sensor reading.
