PI P-611 Series, Руководство пользователя

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3 Product Description
14 Version: 1.2.0 PZ253E P­611 Positioners
3.7 Technical Features
3.7.1 PICMA® Piezo Actuators
P-611 positioners are driven by PICMA® piezo actuators. PICMA® actuators have all-ceramic
insulation and their performance and lifetime are therefore far superior to conventional
actuators. The ceramic insulation layer protects the monolithic piezoceramic block against
humidity and failure due to increased leakage current. In this way, an especially high reliability
is achieved even under extreme ambient conditions. In contrast to motorized drives, there are
no rotating parts or friction. The piezo actuators are therefore free of backlash, maintenance,
and wear.
3.7.2 Flexure Guides
P-611 positioners have flexure guides for friction-free motion and high guiding accuracy.
A flexure guide is an element that is free of static and sliding friction. It is based on the elastic
deformation (bending) of a solid (e.g., steel) and does not have any rolling or sliding parts.
Flexure elements have a high stiffness and load capacity. Flexure guides are maintenance and
wear free. They are 100 % vacuum compatible, function in a wide temperature range and do
not require any lubricants.
3.7.3 Strain Gauge Sensors (SGS)
Strain gauge sensors derive the position information from their expansion. They are attached at
a suitable position in the drivetrain, where they measure the displacement of the positioner's
moving part against the base body. This type of position measuring is indirect and requires
contact, because the position of the platform is derived from a measurement on the lever,
guide or piezo stack.
The sensors operate in thermally drift-free full bridge circuitry and therefore ensure optimum
position stability in the nanometer range.