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Re pressure measure and others

Question asked by VRFuser on Apr 26, 1999
Latest reply on Apr 26, 1999 by VRFuser
<!DOCTYPE HTML PUBLIC "-//W3C//DTD W3 HTML//EN"><HTML><HEAD><META content=text/html;charset=iso-8859-1 http-equiv=Content-Type><BASE href="file://C:Program FilesCommon FilesMicrosoft SharedStationery"><!DOCTYPE HTML PUBLIC "-//W3C//DTD W3 HTML//EN"><META content='"MSHTML 4.72.2106.6"' name=GENERATOR></HEAD><BODY bgColor=#ffffff><DIV>Hi Mario,</DIV><DIV> </DIV><DIV>Using a 3852A you can measure all of these quantities easily...</DIV><DIV>since you are already using the unit to measure temperature using thermocouples</DIV><DIV>I will assume basic familiarity with programming...</DIV><DIV> </DIV><DIV>This is, necessarily, a quick overview of the techniques of measurement...</DIV><DIV>more detail may be found in most  texts of basic electricity / electronics.</DIV><DIV>I often recommend "Electrical Principles and Practices" by Mazur and Zurlis</DIV><DIV>( American Technical Publishers, 1997), and the ARRL "Radio Amateurs </DIV><DIV>Handbook"  as useful guides... </DIV><DIV> </DIV><DIV>Voltage is the most straightforward measurement, since you have a 44701A</DIV><DIV>voltmeter; a simple parallel connection to the unit under test will suffice.</DIV><DIV>Voltages higher than the input range may be handled by a voltage divider made </DIV><DIV>from two precision resistors.</DIV><DIV> </DIV><DIV>Current measurement requires a series connection inline to the unit under test ; </DIV><DIV>again, currents greater than the highest range may be scaled to fit by use of a </DIV><DIV>simple "shunt" resistance inline which will produce a voltage drop across the </DIV><DIV>resistance which is proportional to the current flow.</DIV><DIV>Many types of "current probes" also exist which typically clamp around a current</DIV><DIV>carrying conductor and sense the magnetic field produced by the current flow,</DIV><DIV>generating in turn an output voltage proportional to the current...</DIV><DIV>see HP or other instrument catalogs.</DIV><DIV> </DIV><DIV>Power may easily be calculated from measured current and voltage :</DIV><DIV>(Watt's Law)           P(watts) = I (amps)  X  E(volts)</DIV><DIV> </DIV><DIV>As for pressure measurement, there are many forms available, from simple </DIV><DIV>strain-gage transducers to transducers which perform all signal conditioning </DIV><DIV>internally and produce a proportional output voltage or current...</DIV><DIV>as an introduction to transducer technology I recommend the excellent (and free!)</DIV><DIV>catalog / handbooks of Omega Engineering Inc. , Stamford, CT 06907</DIV><DIV>|<A href=""></A>> , although many others also manufacture equivalent units.</DIV><DIV>HP offers several multiplexer units for the 3852 which will accept direct </DIV><DIV>strain-gage inputs (static or dynamic) and condition them appropriately...</DIV><DIV>|<A href=""></A>> </DIV><DIV> </DIV><DIV>I hope you find this helpful !</DIV><DIV> </DIV><DIV>Phil</DIV><DIV><BR>Phil Van Heurck<BR>Test Engineer<BR>Trace Laboratories - Central<BR>1150 West Euclid Avenue<BR>Palatine, IL  60067<BR>voice 847.934.5300<BR>fax    847.934.4600<BR>|<A href=""></A>><BR></DIV></BODY></HTML>