Elvaco offers temperature and humidity sensors, both for indoor and outdoor environments. The product line enables simple and cost-effective metering, which enables a more effective use of energy and a better real-estate climate. Sensors are available with M-Bus or Wireless M-Bus communication, as well as with or without display.  


CMa11w - Indoor temperature/humidity sensor, Wireless M-Bus

CMa11w is a 1-way wireless M-Bus temperature and humidity sensor for indoor use. The sensor offers high accuracy, user-friendliness and a long battery-life (up to 12 years), which makes it the optimal choice for tenant owners. Readouts and configuration are easily performed via wireless M-Bus or by using a mobile phone (via NFC).


Casing material:
ABS UL94-V0, white
Protection class:
Dimensions (w x h x d):
80 x 80 x 25 mm
75 g

Electrical connections

Supply voltage:
Battery, life span 12 years

Electrical characteristics

Environmental specifications

Operating temperature:
-20 °C to +55 °C
Operating humidity:
0 to 95 %, no condensation
Operating altitude:
0-2000 m
Pollution degree:
Degree 2
Usage environment:
Storage temperature:
-40 °C to +85 °C
Measurement range, temperature sensor:
-20 °C to +55 °C
Measurement range, humidity sensor:
0 % RH to 100 % RH

Temperature sensor, margin of error

Temperature: 10 °C to 30 °C:
Temperature: 0 °C to 10 °C:
Temperature -10 °C to 0 °C:
Temperature: below -10 °C or above 30 °C:

Humidity sensor, margin of error

Humidity: 10 % RH to 90 % RH:
±2% RH
Humidity: below 10 % RH or above 90 % RH:
±4% RH

User interface

LCD diplay:
Momentary values:
Temperature, humidity, status
Historic values:
Average value over the last hour and last day


M-Bus slave
M-Bus standard:
EN 13757-4. Communication by T1

Wireless M-Bus

Integrated M-Bus Master

Wireless M-Bus Receiver

M-Bus slave interface

Frequency, Wireless M-Bus:
868.95 MHz
Transmit power:
10 mW
Transmit interval:
6 minutes
Wireless M-Bus modes:
-104 dBm


Data storage (examples)

Mobile Network

Fixed Network (Ethernet)



EN 61000-6-2, EN 61000-6-3

Connections and Interfaces


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