{"id":1286,"date":"2013-07-18T10:17:24","date_gmt":"2013-07-18T09:17:24","guid":{"rendered":"https:\/\/www.sensorex.fr\/meggitt\/?page_id=1286"},"modified":"2022-06-09T10:32:45","modified_gmt":"2022-06-09T09:32:45","slug":"position-measurement-2","status":"publish","type":"page","link":"https:\/\/www.meggittsensorex.fr\/en\/position-measurement-2\/","title":{"rendered":"LVDT"},"content":{"rendered":"<h2 style=\"font-size: 30px!important; color: #658d1b!important;\"><strong>Some features of an LVDT<\/strong><\/h2>\n<hr \/>\n<p>The most significant parameters for LVDT are:<\/p>\n<p><strong>The linearity<br \/>\n<\/strong>This defines the maximum deviation between calibration points and the best straight line drawn through all calibration points; it is expressed as a percentage of the Full Scale Output (FSO). The absolute error is proportional to the displacement. Applications of LVDT\u2019s are usually limited to 500mm.<\/p>\n<p><strong>The sensitivity error<br \/>\n<\/strong>This defines the difference between the theorical sensitivity and the real one determined by linear regression (Meggitt (Sensorex) uses the best straight line method).<br \/>\nThe sensitivity is expressed in m V\/V\/mm. Associated electronics provide a span adjustment, so this error term can be avoided by the end user.<\/p>\n<p><strong>Thermal zero drift and sensitivity shift<br \/>\n<\/strong>From experience, the thermal zero drift is negligible. Therefore, the only thing to consider is the thermal sensitivity shift.<br \/>\nIt is expressed in ppm\/\u00b0C of FS (1ppm=1.10-6).<\/p>\n<p><strong>Excitation frequency influence<br \/>\n<\/strong>LVDT\u2019s specifications are given at ambiant temperature and for a given excitation voltage and frequency (23\u00b0 and 2.2Vrms at 3500 Hz for Meggitt (Sensorex) devices).<br \/>\nThe transducers can be used at other frequencies. Nevertheless, for a given LVDT, some limits determine a change in linearity.<br \/>\nGenerally, Meggitt (Sensorex) LVDT can be used with excitation frequencies from 1,5kHz up to 20kHz.<\/p>\n<p><strong>Magnetic field influence<br \/>\n<\/strong>Meggitt (Sensorex) technology allows the user not to take into consideration the influence of external magnetic fields.<\/p>\n<p><strong>Primary to secondary coil phase shift<\/strong><br \/>\nA few degrees phase shift can be observed between primary and secondary voltage; it gives an error which is integrated in the specified linearity, sensitivity and drift.<\/p>\n<p><strong>Bandwidth<br \/>\n<\/strong>Its limitation (a few hundred Hz) is determined by the associated electronics or by the excitation frequency, not by the transducer itself.<\/p>\n<p>Meggitt (Sensorex) is able to deliver special LVDT which can be used in other modes such as DIFFERENCE\/ SUM (V1-V2\/V1+V2).<br \/>\nThis type of processing can minimize the influence of external parameters (temperature, excitation\u2026)<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Some features of an LVDT The most significant parameters for LVDT are: The linearity This [&hellip;]<\/p>\n","protected":false},"author":6,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-1286","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.meggittsensorex.fr\/en\/wp-json\/wp\/v2\/pages\/1286","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.meggittsensorex.fr\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.meggittsensorex.fr\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.meggittsensorex.fr\/en\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/www.meggittsensorex.fr\/en\/wp-json\/wp\/v2\/comments?post=1286"}],"version-history":[{"count":0,"href":"https:\/\/www.meggittsensorex.fr\/en\/wp-json\/wp\/v2\/pages\/1286\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.meggittsensorex.fr\/en\/wp-json\/wp\/v2\/media?parent=1286"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}