Temperature | humidity controller | IP65 enclosure | PoM

External temperature and humidity sensor OCTHM-R

This sensor controller regulates the humidity and temperature in HVAC applications placed in harsh environments or outdoors, using Modbus RTU. It also measures the ambient light levels.

The supply voltage is 24 V DC PoM, which means that Modbus RTU communication and a 24 VDC power supply can be connected using a single RJ45 connector. Modbus RTU communication allows the sensor algorithm to control an EC fan, an AC fan speed controller, or a damper actuator directly. Modbus RTU is used to access all measurements and the output value and allows for the adjustment of all settings.

The ambient light sensor can be used in many applications to regulate the ventilation system based on how many people are in the room.

In a variety of industries, including manufacturing, agriculture, electronics, and more, controlling temperature and humidity in challenging environments is essential. Extreme temperatures, high humidity, low humidity, and exposure to dust, chemicals, or other contaminants can all be considered harsh environments. To withstand these harsh conditions, temperature and humidity sensors for harsh environments must be robust and long-lasting.

How does it function?

This HVAC sensor controller measures ambient light level, relative humidity, and temperature. The dew point is determined using the temperature and humidity measurements. These values can all be accessed through Modbus RTU communication. Also by means of Modbus RTU communication, the sensor algorithm can directly control an EC fan, an AC fan speed controller, or a damper actuator. In proportion to the measured temperature and relative humidity, the output value changes. For instance, when temperature or relative humidity are getting close to their maximum values, the fan will run more quickly or the damper will open.

Reduced installation time

It only takes one RJ45 connector to connect this sensor. Power over Modbus (PoM) refers to the connection of Modbus RTU communication and a 24 V DC power supply via one single cable. These power supplies have short-circuit, overload, and overvoltage protection. A supply voltage of 24 V DC improves the safety and dependability of your installation.

Simple to use

There is very little configuration needed for this sensor. After installation, it is practically immediately usable. Region and season are frequently factors that affect temperature and relative humidity. During installation, these parameters are still set to their correct values. The other default settings should be sufficient for the majority of applications. However, if necessary, they can be changed using the corresponding Modbus registers. You can, for instance, modify the temperature or relative humidity range or the values for active and standby level. A list of all programmable settings is provided by the Modbus register map.

Harsh environments

The enclosure offers an IP65 protection against the entry of dust and water. It can be fixed on a wall or flat surface. Each sensor is calibrated and tested in our factory. We use sensor elements and components of high quality. This ensures the long-term stability and accuracy of this HVAC sensor controller. To ensure optimal performance, it should be protected from direct sunlight.