- February 28, 2006
- National Instruments Corporation
NEWS RELEASE – Feb. 28, 2006 – National Instruments further extends its low-level measurement PXI offering for digital multimeters and data acquisition devices with the new NI PXI-4022 guard and current amplifier. This signal conditioning accessory enhances the resistance, capacitance and current measurement capabilities of the latest PXI products from the company, including the NI PXI-4071, the industry’s most accurate 7½-digit digital multimeter (DMM) and NI M Series data acquisition modules. The high-speed, high-precision amplifier is ideal for in-circuit testers and manufacturing defect analyzers in automated test equipment and consumer electronics applications.With the guarding function of the PXI-4022 amplifier, engineers can perform 6-wire resistance measurements for resistors in a network on complex printed circuit board layouts or cable test applications. The 6-wire resistance technique improves the accuracy of the existing 4-wire resistance technique available on most DMMs. The four wires in a DMM provide the source/sense capability to eliminate the effects of lead resistance. The two additional wires in a 6-wire configuration add a unity-gain amplifier to guard the resistor under test against adjacent resistances or contamination across a probe fixture, which would skew the test data. Without this capability, it is often impossible to make accurate measurements on resistors in complex circuit board layouts. This 6-wire capability also works on capacitance measurements available with the NI PXI-4072 6½-digit DMM with LCR capability.For low-current measurements, the PXI-4022 module includes high-precision resistors that create a feedback current amplifier to improve measurement accuracy. Often, the sensitivity and resolution of a current-measuring device do not give accurate measurements in the sub-nanoamp range. In addition, these low levels of current are highly affected by physical properties of active devices, such as burden voltages, that can increase current error. Using the module’s amplifier and resistor network, engineers can minimize much of this measurement burden voltage, accurately measuring picoamps with femtoamp noise. Also, as a current-to-voltage conversion circuit, this functionality can make it possible for engineers to measure low-level currents (nanoamps) with a multifunction data acquisition device such as an 18-bit NI M Series data acquisition module.The PXI-4022 guard and current amplifier features a single function call for programming for simple setup and integration with existing systems. The module works with all of the DMMs in the NI 407x product family and all M Series data acquisition modules. The guard and current amplifier also works with all PXI modular instruments and switches for in-circuit test or manufacturing defect analyzers. Engineers can program the module with the NI LabVIEW graphical development environment. About PXIPCI eXtensions for Instrumentation (PXI) is an open specification governed by the PXI Systems Alliance (www.pxisa.org) that defines a rugged, CompactPCI-based platform optimized for test, measurement and control. It is supported by more than 65 member companies and more than 1,150 products are available. PXI products are compatible with the CompactPCI industrial computer standard and offer additional features such as environmental specifications, standardized software and built-in timing and synchronization.About National InstrumentsFor 30 years, National Instruments has been a technology pioneer and leader in virtual instrumentation – a revolutionary concept that has changed the way engineers and scientists in industry, government and academia approach measurement and automation. Leveraging PCs and commercial technologies, virtual instrumentation increases productivity and lowers costs for test, control and design applications through easy-to-integrate software, such as NI LabVIEW, and modular measurement and control hardware for PXI, PCI, PCI Express, USB and Ethernet. Headquartered in Austin, Texas, NI has more than 3,800 employees and direct operations in nearly 40 countries. For the past seven years, FORTUNE magazine has named NI one of the 100 best companies to work for in America.
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