Product overview


The product has two main purposes:

  • Measure outdoor temperature at high precision via M-Bus

  • Measure outdoor humidity at high precision via M-Bus

Application description

The CMa20 is an M-Bus communicating temperature and humidity sensor for outdoor use.

CMa20 is the ideal product for temperature and humidity report of outdoor climate. The high accuracy sensor and user friendly handling makes the CMa20 the perfect choice for outdoor climate logging.

The CMa20 should be used in the following scenarios:

  • Outside measure of temperature and/or humidity

  • Attic monitoring of temperature and/or humidity

  • Cellar monitoring of temperature and/or humidity

  • Other bad environment conditions


If measurement of temperature and humidity is needed for indoor use, see Elvaco AB product CMa10 Indoor M-Bus temperature and humidity sensor.

Parts overview

  1. Service connector

  2. M-Bus in

  3. M-Bus out

  4. Sensor pipe

  5. Wall mounting

  6. Wiring lead-through

Factory default settings

Table 126. Factory defaults



M-Bus Baud rate

2400 Bit/s (M-Bus slave baud rate)

M-Bus primary address

0 (slave not installed)

M-Bus secondary address

Serial number (revert secondary address to serial number)

Type approval

Refer to Declaration of Conformity.

Was this article helpful?

0 out of 0 found this helpful
Have more questions? Submit a request

Comments (0 comments)

Article is closed for comments.