In industrial and information technology environments, the precise measurement of electrical currents plays a crucial role. High-availability systems, energy-efficient production processes, and continuous monitoring of installations require sensors that are precise, safe, and seamlessly integrable. The HW-group Sensor 0–20mA 1W-UNI meets exactly these requirements. As a galvanically isolated direct current sensor, it measures current values in the range of 0 to 20 milliamps and accurately converts them into the 1-Wire-UNI format. This allows almost any industrial signal to be integrated into existing monitoring solutions—from transmitters to process controllers.

The 0–20mA 1W-UNI sensor serves as an interface between classic industrial probes with 0–20mA outputs and modern network monitoring systems such as Poseidon2 or Ares. Its main purpose is to convert electrical measurement signals into digital data sets that can be processed further via LAN, GSM, or cloud platforms. With its galvanic isolation and precise calibration, the sensor ensures maximum accuracy and operational reliability. Whether used for pressure monitoring, level measurement, or current flow control—this compact device offers stable and accurate signal transmission that meets industrial standards.

Thanks to its compatibility with HW-group products, the sensor is designed for a wide range of applications. Operators of server rooms, data centers, production facilities, or utility networks can use the current sensor flexibly to track the status of electrical currents in real time. Direct connection to the 1-Wire-UNI bus allows for easy integration into existing monitoring networks, enabling measurement data to be automatically documented and analyzed. This technology represents a shift from traditional stand-alone measurements to intelligent, networked current monitoring.

A particular highlight is the ability to connect external industrial probes of the “Source” type with four-wire connections. This makes the 0–20mA sensor ideally suited for linking standardized industrial outputs with HW-group measurement systems. This allows pressure transmitters, temperature sensors, or current transformers with 0–20mA interfaces to be integrated into a unified monitoring concept—including central control, alarm management, and real-time data collection.

Features and Technical Advantages

The 0–20mA 1W-UNI sensor offers a variety of technical features that simplify its application in industrial processes while ensuring the highest accuracy. The converter function is supported by precise calibration and galvanic isolation, enabling error-free measurements even in complex system structures.

• Measuring range 0–20 mA (Type “Source”, four-wire).
• Galvanically isolated input to avoid interference and protect sensitive electronics.
• Conversion to 1-Wire UNI data format (RJ11 connectors).
• Measurement accuracy ±2% of full scale.
• Resolution of 0.1 mA for fine signal changes.
• 8-point calibration for precise adaptation to external sensor characteristics.
• Simple plug-and-play connection via two RJ11 ports for daisy-chaining.
• Flexible power supply via bus or external 12–30 V DC input.

Versatile Applications

The HW-group Sensor 0–20mA 1W-UNI can be used universally in environments where signals from industrial sensors need to be monitored and digitized. With its robust design and simple connectivity, it is equally suitable for stationary and mobile monitoring setups.

In server rooms or data centers, for example, the 0–20mA sensor can be used to monitor current transformers. Changes in current are detected and reported in real time, enabling early detection of potential faults. In production environments, the sensor can measure tank fill levels or pressure in hydraulic systems. Temperature transmitters or flow meters with a 0–20mA output can also be easily integrated.

Through its network connection, all detected signals can be centrally visualized and recorded. LAN, GSM, or LTE interfaces trigger alarms when critical thresholds are reached. Security-related infrastructures or power distribution systems benefit from continuous monitoring and rapid response in the event of malfunctions.

Integration into Monitoring and Control Systems

Thanks to its compatibility with all HW-group systems, the 0–20mA 1W-UNI sensor can be flexibly integrated into existing networks. Especially when combined with devices such as Poseidon2, Ares, or HWg-PWR, it demonstrates its full potential. The Poseidon2 system, for example, enables measurement data to be transmitted over the local network, while Ares ensures monitoring via mobile networks. The data is transmitted to central systems using protocols such as SNMP, XML, or Modbus/TCP, giving operators complete transparency and control over all connected sensors.

Additional value is provided by the free HWg-PDMS software, which stores all recorded measurement data, displays it graphically, and exports it in Excel format. Combined with the SensDesk cloud portal, current loop measurements can be monitored remotely. Using mobile apps on Android or iOS devices, statuses can be accessed at any time—an indispensable advantage for technicians managing multiple sites.

Easy Installation and Adjustment

Installing the sensor is straightforward and requires no special tools. The 0–20mA current loop is connected via screw terminals, while the RJ11 ports are intended for connection to the 1-Wire-UNI network. If required, the sensor can be powered by an external DC supply (12–30 V DC). Alternatively, bus power from connected HW-group devices is sufficient, provided no more than two sensors are operated per active port.

The optionally available USB calibrator for 1W-UNI allows for individual calibration. This ensures that measurements are precisely matched to the respective industrial processor or signal source. For example, a pressure sensor can be adjusted exactly to the system being measured, further improving accuracy. These calibration options make the 0–20mA sensor a particularly flexible solution for demanding measurement tasks.

Robustness and Reliability

The 0–20mA 1W-UNI sensor is specifically designed for use in harsh environments. Its housing provides IP23 protection, making it resistant to dust and splashing water. The operating temperature range from –40 °C to +85 °C ensures reliable operation both in climate-controlled server rooms and industrial production halls. Galvanic isolation reliably prevents electrical feedback into other devices. This robustness enables years of continuous operation without loss of performance or drift in measurement values.

Application Examples

• Monitoring current profiles in industrial processes and plant automation.
• Pressure monitoring in hydraulic or pneumatic lines via external transmitters.
• Fill level measurement in tanks, silos, or pipelines.
• Recording sensor output from energy meters or grid transformers with a 0–20mA output.
• Integration into remote monitoring solutions with GSM or LTE data transmission.
• Combination with environmental monitoring sensors such as temperature or humidity probes.
• Logging process data for energy optimization and efficiency improvement.

Integration with HW-group Monitoring Devices

The sensor’s full capabilities are realized when used together with HW-group systems. Connected to Poseidon2, the sensor can send measurement data over LAN to the network. When used with the HWg-Ares device, wireless communication via GSM is also possible—ideal for sites without fixed connectivity. The HWg-PWR energy management system can additionally correlate consumption values to create a comprehensive energy profile.

Using tools like HWg-PDMS, the data is not only collected but also processed, visualized, and archived. A dedicated trend chart can be created for each connected current source to perform long-term trend analysis. Threshold violations automatically trigger alarms via e-mail, SMS, or SNMP traps. This makes the 0–20mA sensor an integral part of a complete energy monitoring system that protects technical rooms, industrial installations, and building infrastructure.

Calibration and Fine Adjustment

For demanding applications, the sensor offers precise calibration using the 1W-UNI USB calibrator. This function allows the measurement curve to be individually adapted to external industrial components. Depending on the measurement probe used (e.g., pressure or temperature sensor), the user can precisely adjust the full linear or segmented measurement range. This enables both standardized measurements and application-specific control.