Signal isolation
What is a signal isolator?
PR electronics offers a comprehensive range of signal isolators and converters designed to ensure stable, accurate, and reliable signal transmission in any industrial environment.
These devices are the cornerstone of a robust process control system, providing superior resistance to electromagnetic interference (EMI) while converting and amplifying signals for maximum compatibility and performance. By protecting sensitive equipment, eliminating ground loops, and guaranteeing signal integrity, our isolation solutions provide peace of mind and unparalleled performance.
If you require assistance in finding the right device, please do not hesitate to contact us.
Slimline 6.1 mm housing
Response time < 7 ms
Simple - no setup needed
- Slimline 6.1 mm housing
- Response time < 7 ms
- DIP switch configuration
- Slimline 6.1 mm housing
- Response time <7 ms
- Simple - no setup needed
Slimline 6.1 mm housing
Splitter function: 1 in -
2 outDIP-switch configured
SSlimline 6.1 mm housing
2-wire supply >15 V
Output for current and voltage
- Slimline 6.1 mm housing
- Conversion of voltage and current bipolar process signals to unipolar signals
- Response time <7 ms
- Slimline 6.1 mm housing
- Excellent accuracy and high output load stability
- Splitter function: 1 signal in and 2 signals out
- Slimline 6.1 mm housing
- Low input voltage drop and fast response time
- Excellent accuracy and high load stability
- Slimline 6.1 mm housing
- Low voltage drop and fast response time < 5 ms
- Excellent accuracy, better than 0.05% of span
- 1- or 2-channel version
- Loop supply > 17.1 V
- Universal supply by
AC or DC
- 1- or 2-channel version
- 2-wire supply > 17 V
- Universal supply by AC
or DC
- 1-, 2- and 4-channel galvanic isolation
- Low response time
- High noise suppression
- 24 VDC supply via power rail or connectors
- Active and passive mA input
- SIL2 / SIL3 Full Assessment
- 24 VDC supply via power rail or connectors
- High active output load 725 Ohm / 20 mA
- SIL2 certified via Full Assessment
- Interface for NAMUR sensors and switches
- 1 or 2 channels
- SIL 2-certified via Full Assessment
- Universal driver for solenoids, acoustic alarms and LEDs
- 1 or 2 channels
- SIL 2-certified via Full Assessment
- Input: NAMUR, NPN, PNP, Tacho, TTL , S0 & switches
- Output: Universal mA / V or relay
- Power supply 16.8 VDC…31.2 VDC
- Input: NAMUR, NPN open collector, contact
- Output: 2 x relay or NPN transistor output
- Power supply 16.8 VDC…31.2 VDC
Why signal isolation matters in harsh industrial environments
Industrial environments are rife with challenges, from the electrical noise generated by motors and variable frequency drives to unpredictable voltage transients and ground potential differences.
These issues can corrupt process signals, leading to inaccurate measurements, control system instability, and even equipment failure. PR electronics' isolators are engineered to solve these problems, maintaining pristine signal quality in the harshest conditions.
Our extensive portfolio, from compact 6 mm devices to SIL-certified interfaces, ensures a solution for every application.
The power of galvanic isolation
At the heart of our technology is galvanic isolation, a technique that physically separates the input, output, and power supply circuits to break the electrical path between them.
This fundamental feature solves some of the most common and frustrating problems in industrial automation, including ground loops, common-mode voltages, and damaging electrical transients.
By protecting your sensitive measurement and control systems from these disturbances, our isolators, including the versatile 3000, 4000, 5000, and 9000 series, provide a clean, stable signal, resulting in more accurate and reliable process data.
Compact and fast: High-density 6 mm isolation
When panel space is at a premium, our 3000 series of slimline 6.1 mm isolators deliver exceptional performance in an ultra-compact package. These devices offer market-leading packing density, allowing you to mount up to 50 devices or up to 100 channels within just 30 cm of DIN rail space.
With fast response times, often less than 7 ms, they are ideal for critical control loops where speed is essential. The ability to stack these units both vertically and horizontally without requiring an air gap provides design flexibility, while their low power consumption helps reduce operational costs.
Key products like the PR 3103 Isolated Repeater, PR 3104 Isolated Converter, and PR 3114 Isolated Universal Converter exemplify this combination of density and performance.
HART transparency for smart instrumentation
Modern process automation relies on smart instrumentation, and maintaining the flow of digital HART data is crucial for advanced diagnostics and asset management.
PR electronics' HART transparent repeaters are specifically designed to preserve this communication channel during signal isolation. Devices like the PR 5106A (safe area) and PR 9106B (Intrinsically Safe) allow the digital HART signal to pass through the isolator uninterrupted. This enables engineers to remotely configure, calibrate, and diagnose smart field devices without ever needing to bypass the isolation layer, ensuring both safety and operational efficiency.
Functional safety: SIL-certified isolation for critical applications
In applications where failure can have serious consequences, a Safety Instrumented System (SIS) is essential.
Our range of SIL-certified isolators provides the reliability needed for these critical safety loops.
Devices like the PR 9106A HART Transparent Repeater (SIL2 / SIL3), PR 9202A Pulse Isolator (SIL 2), and PR 9116A Universal Converter (SIL 2) have undergone rigorous assessment to ensure their performance in protecting personnel, equipment, and the environment.
This makes them the trusted choice for the most demanding applications in the oil & gas, chemical, and power generation industries.
Versatility across all signal types
Our extensive isolation portfolio is designed to handle nearly any signal type you may encounter. We offer a wide range of solutions for standard analog signals (mA, V), temperature signals from RTD and TC sensors, and frequency or pulse signals from NAMUR, NPN, and PNP sensors.
Whether you need a universal frequency converter like the PR 3225 or a dedicated pulse isolator like the PR 9202A, you can be confident that a PR electronics solution exists to meet your specific needs, providing unmatched versatility from a single supplier.
Your foundation for a reliable process
High-quality signal isolation is the foundation of any reliable and accurate process control system.
PR electronics' solutions deliver a powerful combination of benefits: exceptional noise immunity, space-saving design, certified safety, and long-term reliability.
From simple non-critical applications to the most demanding safety loops, we offer an isolator for every need. We invite you to explore our comprehensive range and contact our experts for advice on designing the ideal isolation strategy for your process.
Need help finding the right isolator?
Unsure which isolator or converter fits your application? Send us your requirements and our specialists will recommend the right device for your process.
What is galvanic isolation, and why is it essential in industrial signal conditioning?
Galvanic isolation is the electrical separation of two circuits such that no direct conductive path exists between them — only the signal is transferred (inductively or optically). In industrial environments, field instruments and control systems often have different ground potentials, sometimes differing by tens or hundreds of volts. Without galvanic isolation, these potential differences create ground loop currents that corrupt the 4-20 mA measurement signal with errors and noise. PR electronics isolation devices (e.g., PR 3103, PR 3108) provide 2.5 kVAC test isolation to eliminate these issues.
What is the PR 3103 isolated repeater, and what makes it unique?
The PR 3103 is a 1:1 isolated repeater in PR electronics' ultra-compact slimline 6.1 mm housing. It requires no setup — simply install and it transparently passes the 4-20 mA signal with galvanic isolation. Key specifications include accuracy better than 0.05% of span, response time under 7 ms, a signal-to-noise ratio exceeding 60 dB, and a cut-off frequency above 100 Hz. At only 6.1 mm wide, approximately 163 units can be mounted per meter of DIN rail, making it ideal for high-density control cabinet installations.
What SIL-rated isolation products does PR electronics offer?
The 9000-series isolation devices carry SIL 2/3 full assessment certification per IEC 61508. These include the PR 9106A (HART transparent repeater), PR 9107A (HART transparent driver), PR 9202A (pulse isolator), and PR 9203A (solenoid/alarm driver). They are designed for safety instrumented systems where functional safety certification is mandatory. The 9106A and 9107A maintain HART transparency while providing SIL-rated galvanic isolation, enabling safety systems to use HART-based smart transmitters for both process control and safety functions.
What is the PR 3202 pulse isolator/switch amplifier, and where is it used?
The PR 3202 accepts digital input signals from NAMUR sensors, NPN proximity switches, or dry contacts, and provides electrically isolated relay or transistor outputs. It is used to interface digital/discrete signals across isolation boundaries — for example, connecting a pulse output from a flow meter in one grounding zone to a totalizer or PLC counter in another. The device prevents ground loops on digital circuits, which can cause false counts or missed pulses. It maintains the signal timing integrity required for accurate flow measurement.
What is the PR 3225 universal frequency converter?
The PR 3225 is a slimline 6.1 mm programmable frequency converter that accepts multiple digital input types (NAMUR, NPN, PNP, Tacho, TTL, S0, switches) and converts them to an isolated analog mA/V output, frequency output, or relay output. It can also perform frequency-to-current, frequency-to-frequency, and frequency scaling conversions. Programming is done via the PR 4590 ConfigMate. Applications include converting turbine flow meter pulse outputs to 4-20 mA for a DCS, or scaling frequency signals between incompatible instruments.
What is the maximum number of slimline isolators that can be mounted on a single DIN rail?
The PR 3000-series slimline isolators are 6.1 mm wide and can accommodate approximately 163 units per meter of standard 35 mm DIN rail (EN 60715). This extreme density is a key advantage in applications requiring large channel counts in limited cabinet space, such as offshore platforms, chemical plants, and power stations. Each unit weighs approximately 70 g, so a full meter of isolators weighs about 11.4 kg. The devices clip directly onto the DIN rail without additional mounting hardware.
How do PR electronics isolation products handle EMC (electromagnetic compatibility) in harsh industrial environments?
PR electronics isolation devices are designed and tested to exceed standard EMC requirements. The PR 3103, for example, achieves less than ±0.5% of span immunity influence under standard EMC testing, and less than ±1% of span under extended EMC testing per NAMUR NE21 criterion A. All isolation products carry CE marking per EMC directive 2014/30/EU. The combination of high galvanic isolation voltage (2.5 kVAC), signal-to-noise ratio exceeding 60 dB, and fast response times ensures that measurement signals remain clean even in environments with variable frequency drives, motor starters, and other sources of electromagnetic interference.