Signal isolators are widely used in industrial automation, process control, and instrumentation systems to provide electrical isolation, reduce ground-loop interference, and improve the reliability of signal transmission. Depending on the application, they can also convert signal types, split outputs, supply field transmitters, or provide interfaces for intrinsically safe circuits. The following eight companies offer signal isolators, signal conditioners, or closely related industrial interface products.
1. Phoenix Contact signal isolator
Phoenix Contact develops electrical connection, automation, and industrial interface solutions. Its signal isolator portfolio includes the MINI Analog, MINI Analog Pro, and MACX Analog product families, which provide signal isolation, conversion, filtering, and amplification for analog and digital process signals. Selected models also support intrinsically safe applications and functional safety requirements.
2. Weidmüller signal isolator
Weidmüller provides industrial connectivity and automation electronics, including signal isolators and measuring transducers. Its ACT20 series signal isolator supports analog signal conversion, galvanic isolation, frequency measurement, and process monitoring.
The range includes configurable modules for current and voltage signals, as well as specialized interfaces for hazardous-area applications. The compact PICOPAK family is another option for space-constrained control cabinets.
3. Masibus signal isolator
Masibus supplies industrial instrumentation and process automation products, including dedicated signal isolators. Its 9000E and 9000Ex series signal isolator are designed for analog signal isolation and transmitter interfacing. Depending on the model, these devices can isolate 4–20 mA signals, provide transmitter power, and repeat signals to equipment in a separate electrical circuit. The 9000Ex series also addresses signal interfacing involving hazardous areas.
4. Moore Industries signal isolator
Moore Industries is an industrial process instrumentation manufacturer known for signal interface and process measurement products. Its product portfolio includes signal isolators and signal conditioners designed to interface field instruments with control systems. Depending on the model, these devices can support analog signal isolation, conversion, and distribution in process automation applications.
5. Pepperl+Fuchs signal isolator
Pepperl+Fuchs specializes in industrial sensor technology and explosion protection. Its K-System includes signal conditioners and isolated barriers for transferring signals between field devices and control systems. The portfolio covers analog and digital signals, transmitter power supplies, switch amplifiers, and interfaces for intrinsically safe circuits in hazardous locations. Selected products also offer safety-related approvals and Power Rail installation options.
6. Acromag signal isolator
Acromag develops industrial measurement, signal conditioning, and input/output solutions. Its 600T series includes isolated transmitters, signal isolators, and signal splitters with single-, dual-, and multi-channel configurations. Depending on the model, supported inputs include current, voltage, temperature, and resistance signals. These products are used in process monitoring, industrial control, and applications requiring isolated signal distribution.
7. Multispan signal isolator
Multispan offers industrial instrumentation and process control products, including dedicated signal isolators. Its MI-631 and MI-632 models provide analog signal isolation and conversion for common industrial signals such as 4–20 mA and 0–10 V DC. Depending on the configuration, the devices support single or dual outputs and three-way isolation between input, output, and power supply. They can be used for field signal interfacing, signal distribution, and factory automation.
8. Radix signal isolator
Radix manufactures industrial instrumentation and automation products, including signal isolators and signal converters. Its portfolio covers analog current and voltage signals, temperature sensor inputs such as RTDs and thermocouples, and configurable output signals. Models such as the SCC331 and SCC332 support single- and dual-output configurations, while selected models offer HART compatibility or RS-485 Modbus RTU communication. These options support process measurement, signal conversion, and integration with industrial control systems.
Conclusion
Choosing the right signal isolator depends on signal compatibility, isolation requirements, measurement accuracy, installation conditions, and application-specific certifications. The eight manufacturers listed above offer a range of solutions for industrial automation and process instrumentation, each with different product configurations and capabilities. Before making a selection, compare the technical specifications of individual models to ensure compatibility with your control system and operating environment.
