Expanding the functionality of HP4284A precision LCR meter through measurement system integration

Abstract

For many applications where frequency resolution is not critical, accurate impedance measurements from 20 Hz to 1 MHz can be obtained by HP4284A precision LCR meter. HP4284A is based on the auto-balancing bridge method which offers high accuracy over wide impedance range and relatively wide frequency coverage. In this paper we present a novel integrated architecture of the impedance measurement system. We have built the system around a PC, connected through Agilent 82357A USB/HPIB interface to the HP 4284A LCR impedance meter. Innovative and user friendly control of the instrument is accomplished by the computer application, which we have developed from scratch using the C# programming language and .NET 2.0 framework. The software application controls the instrument parameters and performs measurements through a defined measurement protocol. It enables both online and offline graphical presentation of measured data. To demonstrate the capabilities of the integrated impedance measuring system we present impedance measurements on a simple three-element RC network and on a physiological saline.