Precise control of temperature and humidity plays a key role in many modern industries – from food production and laboratory technology to meteorological applications. The Wiesemann & Theis Web‑Thermo‑Hygrometer ++ is an advanced sensor designed to deliver reliable data even in extremely humid or demanding environments. Developed for continuous operation and high measurement accuracy, this device combines state‑of‑the‑art sensor technology, integrated network services, and a sophisticated data logging function. It is the ideal solution for any environment where stability, precision, and traceability of climate data are critical.

The Web‑Thermo‑Hygrometer ++ impresses with a dew‑resistant sensor that operates drift‑free even under continuously high relative humidity. This distinguishes it from conventional hygrometers, which tend to lose accuracy quickly in humid environments. Complemented by high‑resolution temperature measurement and automatic dew point calculation, this system provides targeted protection against condensation risks. Measurement data can be accessed in real time via a browser‑based web interface or open IoT protocols. With MQTT, REST, and OPC UA support, the device meets all requirements for smart factory architectures in line with Industry 4.0.

Precision Sensor Technology for Demanding Applications

The Web‑Thermo‑Hygrometer ++ is specifically engineered for applications involving high humidity levels or variable environmental conditions. The combined temperature and humidity sensor provides accurate, stable data with minimal drift. The fully encapsulated sensor electronics make the device resistant to condensation and chemical exposure, ensuring long‑term measurement stability. This makes it ideally suited for laboratories, test benches, meteorological stations, and production environments with high steam or dust exposure.

With a measurement range of ‑20 °C to +80 °C and 0 to 100 % RH, the device covers the entire climatic spectrum relevant to research, manufacturing, and storage applications. Even with fluctuating temperatures, measurement accuracy remains consistent. Dew point calculation is performed automatically and displayed in real time both via the web interface and through integrated network protocols. This allows users to detect and prevent critical condensation points early.

Technology for Digital Networks

As a fully integrated component of modern IoT infrastructures, the Web‑Thermo‑Hygrometer ++ communicates via standard open protocols such as OPC UA, MQTT, and REST API. This enables direct integration into control systems, SCADA applications, and building or process automation environments. Developers benefit from interfaces such as Modbus‑TCP, HTTP, or TCP/UDP sockets, which allow the creation of custom applications or dashboards. All communication channels are encrypted and comply with strict IT security standards.

The W&T Cloud provides extensive options for remote monitoring and data evaluation. Measurement values are stored centrally and can be accessed via an internet browser or mobile device. Users can view alarms, energy reports, and trend charts without installing additional software. User permissions, data history, and device configurations are all managed through the cloud – ideal for distributed sites or globally operating organizations.

Technical Specifications

• Temperature range: ‑20 °C to +80 °C
• Humidity range: 0 to 100 % RH (dew‑resistant)
• Dew point calculation: Real‑time determination with visual display
• Data logger: Records for 12 weeks up to 20 years (depending on interval)
• Protocols: MQTT, OPC UA, REST API, SNMP, Modbus‑TCP
• Alerts: Up to 12 configurable alarms via e‑mail, SNMP, Syslog
• Interfaces: HTTP, TCP/UDP sockets, Sensobase, ODBC
• Data export: Excel, FTP, or cloud synchronization
• Power supply: Power‑over‑Ethernet (PoE) or external 24 V DC
• Certification: EN 61000‑6‑2, EN 55032 Class B – high interference immunity
• Mounting: DIN rail or wall mounting

Long‑Term Data Storage and Analysis

The integrated data logger stores all environmental data with precise timestamps, enabling complete documentation of climate conditions over weeks, months, or even decades. Adjustable storage intervals make it possible to analyze long‑term trends or evaluate short‑term events. Through export functions or automated FTP transfer, data can be processed for verification, audit procedures, or energy optimization.

The battery‑buffered real‑time clock ensures continuous data logging even during network interruptions. All measured values remain precisely time‑synchronized, ensuring validity for quality assurance or compliance‑critical applications. In combination with the cloud, redundant backup systems are created to prevent data loss.

Advantages of the Web‑Thermo‑Hygrometer ++

• Drift‑free, dew‑resistant sensor technology
• Accurate real‑time monitoring of temperature and humidity
• Dew point detection to prevent condensation damage
• Web‑based dashboard for monitoring without external software
• MQTT, REST, and OPC UA support for IoT integration
• Long‑term storage with configurable intervals
• Automated alerts via e‑mail, SNMP, or Syslog
• Cloud connection for global remote access
• Energy‑efficient Green‑IT design via PoE supply
• Five‑year manufacturer warranty and robust architecture

Application Fields in Industry and Research

• Climate chambers and laboratories: Ideal as a reference sensor for calibration, quality control, and testing.
• Food processing: Monitoring ripening and storage conditions in cheese, mushroom, or bakery production.
• Meteorology and outdoor installations: Long‑term measurement under high humidity and temperature‑critical conditions.
• Pharmaceutical and medical engineering: Documentation of temperature and humidity conditions in storage and clean rooms.
• Green IT infrastructure: Monitoring of cooling efficiency for energy savings in server rooms.
• IoT and automation: Integration into smart factory systems with cloud‑based monitoring.

Green IT – Efficiency through Intelligent Climate Control

In the digitalized industry, energy consumption and resource conservation are key topics. The Web‑Thermo‑Hygrometer ++ not only provides measurement data but also decision‑relevant information that enables optimized climate control. With precise temperature and dew point data, ventilation and cooling systems can be regulated on demand, leading to measurable reductions in energy consumption. Integration into Green‑IT strategies helps companies comply with energy efficiency guidelines and lower emissions without compromising safety or reliability.

Maintenance, Calibration, and Durability

The device features self‑monitoring electronics that continuously analyze sensor status and report deviations. The dew‑resistant sensor minimizes calibration requirements while remaining easy to recalibrate if necessary. The robust, encapsulated electronics ensure years of reliable operation under continuous load. With standardized DIN‑rail mounting, it can be easily integrated into existing setups. W&T underlines the device’s longevity with a five‑year manufacturer warranty – a clear testament to its quality and reliability.

Precision Meets Digitalization

The Wiesemann & Theis Web‑Thermo‑Hygrometer ++ combines high‑precision measurement technology with intelligent network integration. It delivers accurate, drift‑free readings over long periods while offering all the conveniences of the digital world – from cloud access and alerts to IoT connectivity. Thanks to its robust construction and dew‑resistant sensors, it operates reliably and stably even under challenging environmental conditions. This makes it the perfect solution for professionals requiring precise climate monitoring – in research, production, or environmental technology. For those who value reliability, transparency, and digital connectivity, this device represents a future‑ready climate monitoring solution “Made in Germany”.