Data Logging Indoor Air Quality Meter


This data logging Indoor Air Quality (IAQ) Meter has the ability to record samples on internal memory and keep track of registered readings with a time and date stamp. The R9905 features a Nondispersive Infrared (NDIR) CO2 sensor for stable, accurate readings and the option to track live measurements via software.


  • Triple LCD display simultaneously monitors carbon dioxide (CO2), temperature and relative humidity
  • Calculates time-weighted average (TWA) and short-term exposure limit (STEL)
  • Low-drift NDIR CO2 sensor for stable and accurate readings
  • Temperature and relative humidity measurements help determine thermal comfort
  • Easy-to-read backlit LCD display
  • User adjustable audible alarm
  • Data hold, Max/Min and Average functions
  • Record up to 32,000 datapoints and keep track with internal time and date stamp
  • User selectable sampling rate from 1 to 60 mins
  • Low battery indicator and auto shut-off


Measuring Range-4 to 140°F (-20 to 60°C)
Accuracy±1.5°F (±0.8°C)
Measuring Range0 to 100% RH
Accuracy10 to 90% RH: ±3%
<10% & >90% RH: ±5%
Resolution0.1% RH
CO2 (Carbon Dioxide)
Sensor TypeNondispersive Infrared (NDIR)
Measuring Range0 to 30,000ppm
Accuracy0 to 5000ppm: ±(75ppm +3% rdg.)
5001 to 30,000ppm: ±(150ppm +5% rdg.)
Warm-up Time20s
Sampling Rate2s
General Specifications
Backlit DisplayYes
Data HoldYes
Min, Max, Avg FunctionsYes
CO2 Short Term Exposure Limit (STEL)Yes (15 mins)
CO2 Time Weighted Average (TWA)Yes (8 hours)
Datalogging CapabilitiesYes
Real-Time Clock and Date StampYes
Selectable Sampling RateYes (between 1s and 60m59s)
Internal MemoryYes (32,000 datapoints)
AlarmsYes (Low and High)
Auto Shut-offYes (adjustable)
Kick StandYes
Low Battery IndicatorYes
Power Supply9V battery
Battery LifeApprox. 10 hours (continuous use)
PC ConnectivityUSB
Software OS CompatibilityWindows 7 / 8 / 10 / 11
Product CertificationsCE
Operating Temperature32 to 122°F (0 to 50°C)
Storage Temperature-4 to 140°F (-20 to 60°C)
Operating Humidity Range0 to 90%
Storage Humidity Range10 to 75%
Maximum Operating Altitude6561' (2000m)
Dimensions11.2 x 2.6 x 1.5" (284 x 65 x 39mm)
Weight10.7oz (304g)

What's included

  • Indoor Air Quality Meter
  • USB Cable
  • Hard Carrying Case
  • Batteries

You may also like…