Vishay Intertechnology has announced the introduction of the Vishay Nobel AST3IS transmitter. The AST3IS is a high-performance isolation amplifier designed for use with strain-gage transducers in hazardous areas without the need for Zener barriers. Vishay claims this eases earthing design and installation, and reduces costs and maintenance for process weighing systems in applications such as chemical and pharmaceutical manufacturing.
In addition being suitable for use near inflammable materials and in other hazardous environments, the AST 3IS transmitter is also said to achieve higher temperature stability than previous generation models.
The AST3IS features a patented analogue-to-digital converter capable of up to 8,300,000 counts. It features a DIN-rail mount for easy and compact mechanical integration. By building in support for popular communication protocols including RS-485 and MODBUS RTU, the AST 3IS transmitter can communicate with a common process control host without requiring external hardware or additional software. Fieldbus communication is possible via the GATE 3S module available separately. The AST 3IS accepts up to six ATEX-approved load cells of 350 ohms each, and is approved to ATEX II GD.
The AST 3IS operates from -10 degrees C to +40 degrees C, at up to 95% relative humidity. It is also IP20 ingress-resistant, further enhancing usability in a wide range of environments and applications.
The AST 3IS unit features a patented analogue-to-digital converter for superior resolution and conversion speed, and has analogue as well as digital outputs that allow designers to optimise accuracy and response time. Two relay outputs are provided, with short response time allowing the AST 3IS to be used in high-precision level control applications.
Vishay adds that easy set-up and calibration are additional features of the AST 3IS. It can be achieved by using the AST 3IS user interface directly, or by using the deltaCOM configuration tool via a remote PC. DeltaCOM runs on Microsoft Windows operating systems including Windows 95 and Windows NT4.