SENSOTRON - Aparatura Elektroniczna SENSOTRON - Aparatura Elektroniczna przejście do polskiej wersji językowej home pageproductscontact

Indoor Air Quality Monitor


     The Indoor Air Quality Monitor is designed for measuring and recording carbon dioxide concentration (within the range of 0 ÷: 5000 ppm), relative humidity (0 ÷ 100 %), air temperature (10 ÷ 45 °C) and barometric pressure (900 ÷ 1100 hPa). Using batteries is possible long-term automatic recording (approximately two months without battery charging). Setting the recording period every 300 seconds (5 minutes) allows you to work the device for about 31 days. An external power supply is available as well.

     The values measured can be used for identifying ventilation and air-conditioning efficiency, ventilation air change rate and its variation in time due to outdoor weather conditions and occupant activities, infiltration between separated spaces, air quality assessment, etc. Recorded data can be used also for air density and enthalpy assessment.

Indoor Air Quality Monitor, model PS33

Measuring Channel

     A four-beam non-dispersive infrared CO2 concentration sensor (NDIR is applied in the system using the attenuation dependence of a specifically defined infrared radiation band according to a carbon dioxide concentration. The applied measuring method ensures long-term stability and fast dynamic response. The instrument compensates the influence of temperature and barometric pressure changes, on measurement of CO2 concentration. A mini semiconductor sensor is fitted for measuring temperature and relative humidity.


     The Monitor enables for automatic recording of the measured values and their transmission to a PC via universal USB bus. The recording unit of the monitor allows the selection of recording period, record volume and average values between consecutive recordings.

IAQ Monitor connection to the computer via USB

     It is also possible to keep the transmission of the measured values to the computer via ZigBee wireless link and save the data into file. Additionally, you can also enable storage of measurement results within the internal memory and read them from of each of the instruments after the measurements. This solution will provide protection against data loss, for example, by an accidental computer shutdown. The network range can be increased through the use of routers, model PS337.

IAQ Monitor connection to the computer via ZigBee wireless link

   Measurement system consisting of several air quality monitoring can also work with the module PS336, communications coordinator ZigBee module with data recording function. This module combines the functions of a coordinator PS334 and autonomous system recording data sent from IAQ Monitors through a ZigBee. The module is equipped with a DataFlash memory, which may be registered about half million data records from different Monitors. Independently the measurement system used in the PS336 module, each of the Monitor can save your results to your memory. At any time, either at the time of measurement as well as after its completion, registered in the module PS336 data can be uploaded to a computer and saved to a file. Register measurements locally in each of the Monitors can be considered as an additional safeguard to protect against data loss the result of unexpected situations.

Monitors connection with the module PS336 through ZigBee wireless connection PS336 module and IAQ Monitor connection to computer

     The instrument is shipped with software for PCs working in WindowsXP/2000/VISTA and Windows7 environments, both on 32 and 64 bit. The software enables for reading data recorded in the device and save them in a text file (67 000 records). The program allows the user to enter individual correction factors, if such corrections are necessary upon periodical device check.

appearance of the screen of the user program

     Using wireless communication module PS334, you can read and write to files, the current measured values of several meters at a time.

appearance of the screen of the user program


wireless module , model PS 334, connected to a computer, working at 2.4 GHz ZigBee standard. Powered by computer USB port

wireless module, model PS334

wireless module, the coordinator of the data recording function, model PS336, connected to the computer, working at 2.4 GHz ZigBee standard. Supplied during registration from an external AC adapter or the USB connector of your computer.

wireless module, the coordinator with the data recording function, model PS336

wireless router , model PS 337, increases the range of your wireless network, working at 2.4 GHz ZigBee standard. Powered from external power supply adapter or by computer USB port

wireless router, model PS337

Technical data
measuring channel
   measuring ranges
      carbon dioxide concentration, ppm 0 ÷ 5000
      relative humidity, % 0 ÷ 100
      air temperature, °C 10 ÷ 45
      barometric pressure, hPa 900 ÷ 1100
      carbon dioxide concentration, ppm 1
      relative humidity, % 0,1
      air temperature, °C 0,1
      barometric pressure, hPa 1
   expanded uncertainty, 95%
      carbon dioxide concentration, ppm ± (10 + 3 % of measured value)
      relative humidity, % ± 3,5 (on request ± 2)
      air temperature, °C ± 0,5
      barometric pressure, hPa ± 3
   DC voltage, V 12
   supply current, mA 200
   housing (height x width x length), mm 82 x 150 x 75
   weight without the external mains adapter, kg 0,85

The user's guide in PDF Acrobat Adobe format -    reading The user's guide  "e_iaqm_ps33.pdf"