Rotronic CL11 | CO2 data logger

Contact Instrument Solutions

The Rotronic CL11 benchtop display unit is a multiple parameter meter that simultaneously measures and records CO2, humidity and temperature. Equipped with the ROTRONIC HYGROMER® IN-1 humidity sensor, this instrument offers unbeatable value for money. Using the ROTRONIC software package SW2.x, it can be easily set to record as required and data can then be downloaded, saved and analysed.

This instrument is ideal for indoor air quality (IAQ) / indoor environmental quality (IEQ) studies in schools, offices or domestic dwellings.

The Instrument Solutions rental models come complete with: 

1x CL11 temperature, humidity and CO2 data logger with AC power supply, SW2.x software disk, external temperature probe and calibration certificate


  • Measures and logs CO2, relative humidity and temperature
  • ROTRONIC HYGROMER® IN-1 humidity sensor
  • 40,000 data point memory for CO2, humidity and temperature values
  • Maximum, minimum and average values displayed
  • Adjustable audible and visual CO2 alarm
  • Real time clock with backup battery
  • Includes software for configuration and data download


Dimensions      157 mm x 120 mm x 45 mm

Weight approximately      200 g

Range of application       0 to 50 °C / 0 to 100 % rh, non-condensing

Accuracy at 23 ± 5 °C      ± 30 ppm ± 5 % of the measured value, < 2.5 % rh (10...90 % rh), ± 0.3 K

Measuring range      0 to 5,000 ppm; 0 to 100 % rh; - 20 to + 60 °C

Measurement principle      Non dispersive infrared (NDIR) with automatic baseline correction (ABC)

Adjustment points      Automatic calibration, manual calibration at 400 ppm and 35, 80 % rh

Pressure dependence       + 1.6 % reading per kPa

Null drift      < 10 ppm / year

Measured value memory     40,000 values with time stamp, automatic recording (% rh / °C / CO2 / external temperature probe)

Warm-up time     < 1 minute

Long term stability      < 1.5 % rh per year

Humidity sensor      ROTRONIC HYGROMER® IN-1

Temperature sensor     Thermistor

Response time      < 10 sec @ 30 cc / min. flow, < 3 min diffusion time and 4 s

Response time t 63      < 30 s, without filter

Parameters shown      CO2, relative humidity and temperature

Power supply       AC mains with battery back-up of real time clock

Alarm indicators      Adjustable for CO2 measurement

Exploitation software       ROTRONIC SW2.x

Housing      ABS

IP protection rating      IP30

Support documents

  • Download
  • Category
  • File type
  • Download
Rotronic CL11 data sheet.pdf Rotronic CL11 data sheet
Technical document
File type
Adobe Acrobat
Download (795 KB)
Rotronic CL11 user guide.pdf Rotronic CL11 user guide
Technical document
File type
Adobe Acrobat
Download (2 MB)

Common customer questions & answers

QQuestion Can the CL11 run without a mains adaptor?
AAnswer The unit must be connected to a 240v mains supply for the unit to log and run.
QQuestion When logging, how many data points can the CL11 memory hold?
AAnswer The memory can store 40,000 data points. NOTE that this capacity is 10,000 readings for each parameter (time/temp/rh/CO2)
QQuestion When the Rotronic CL11 measures CO2 what is the range in ppm?
AAnswer The measurement range for CO2 is 0 - 5,000 ppm.
QQuestion I don't have a disc drive - how do I download software for the CL11 ?
AAnswer Software can be downloaded directly from the manufactures website - see the Download tab on the product page.
QQuestion Can the Rotronic CL11 run off its own battery?
AAnswer No, the internal battery is for the memory backup only. For logging over a period of time the unit MUST be connected via the mains power supply provided.
QQuestion Will I lose my logging program if there is a break in power while the unit is logging?
AAnswer The unit will hold its logging program for only a few minutes if there is a disruption in the power supply and will resume logging once the power is re-instated. Longer periods would result in the unit having to be re-programmed and re-started.