The Allnet MSR sensor ALL4420 is a combined sensor for humidity and temperature, designed for use in building technology and automation systems. The device features a flat, robust metal housing made of aluminium, suitable for both desktop and wall mounting. Wall mounting is supported by integrated angle brackets, enabling secure and stable installation. The sensor is specifically designed for indoor use and serves for continuous monitoring of environmental conditions in rooms that are controlled and monitored via network and internet connections.

Applications

The ALL4420 is suitable for applications in smart building technology, particularly in systems for energy saving, climate control, and room monitoring. It can be used in office buildings, apartments, server rooms, or production halls where precise measurement of temperature and humidity is required. The data is transmitted to central MSR systems to enable automated control and regulation functions.

Functions and Equipment in Detail

The sensor measures temperature in the range of -40 °C to +125 °C and humidity from 0 % to 100 % RH. The resolution is 0.01 °C for temperature and 0.01 % RH for humidity, enabling detailed representation of environmental conditions. Measurement accuracy is approximately ±0.6 °C across the entire temperature range (typically ±0.2 °C in the range of -20 °C to +90 °C) and approximately ±3 % RH across the entire humidity range (typically ±1.5 % RH in the range of 0 % to 80 % RH). These values are suitable for applications in controlled indoor environments.

Technology Explained Simply

The sensor uses an I2C bus, which allows multiple sensors to be connected to a single sensor port (multiplexing), provided the sensors have two RJ45 connectors, different I2C chip addresses, and configurable IDs. The total cable length must not exceed 100 m. Signal output occurs over the network, enabling data transmission to central control devices. Response time is approximately 86 seconds (t63%) for humidity and more than 2 seconds (t63%) for temperature. Long-term drift is less than 0.03 °C per year for temperature and less than 0.25 % RH per year for humidity, indicating high long-term stability.

Compatibility and Accessories

The ALL4420 is compatible exclusively with MSR central units from the series ALL34xx, ALL350x, ALL4500, and ALL5000. Examples include central units ALL3419, ALL3500, ALL5000v2, and ALL4176. These devices support network integration and central control of sensor data. Compatible accessories include the MSR central unit ALL3500v2 with 4 sensor ports and WLAN, the MSR IO central unit socket outlet strip 6-way (ALL4176v3), and the central unit ALL5000v2 with 16 sensor ports for 48,3 cm ( 19 inch ) mounting. Combining these central units enables scalable and flexible building automation.

Mounting and Installation

Installation is either on a desk or on the wall. Wall mounting is facilitated by integrated angle brackets, allowing secure attachment to a smooth wall surface. Wiring is done via RJ45 connectors, which are connected to the central unit's network. Connection is made via the I2C protocol, enabling direct transmission of sensor data to the central control system.

Advantages in Operation

The sensor offers high measurement accuracy and stability over long periods. The I2C bus technology enables flexible system expansion through multiplexing, allowing multiple sensors to be operated on one port. Integration into existing IP-based building automation systems requires no additional hardware or software modifications. Data is available over the network, enabling remote monitoring and control. The robust aluminium construction ensures long service life and mechanical stability.