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REED R9900 Indoor Air Quality Meter

Model: R9900

REED R9900 Indoor Air Quality Meter-

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Measures carbon dioxide (CO2), temperature, humidity and automatically calculates dew point and wet bulb temperatures.

REED R9900 Offers

This IAQ (indoor air quality) meter simultaneously monitors carbon dioxide, relative humidity, and temperature. The R9900 is capable of automatically calculating wet bulb and dew point temperatures as well as statistical TWA and STEL averages.


  • Triple LCD display simultaneously monitors carbon dioxide (CO2), relative humidity and temperature
  • Automatically calculates dew point and wet bulb
  • Calculates statistical weighted averages of TWA (8 hour time weighted average) and STEL (15 minute short term exposure limit)
  • User adjustable audible alarm
  • Data hold, Max/Min and average functions
  • Low battery indicator and auto shut off

REED R9900 Specifications

Measuring Ranges 14 to 140°F (-10 to 60°C)
Accuracy ±0.9°F (±0.6°C)
Resolution 0.1°F/°C
Measuring Range 0 to 99.9% RH
Accuracy ±3% (10 to 90% RH)
±5% (<10% & >90% RH)
Resolution 0.1% RH
CO2 (Carbon Dioxide)
Measuring Range 0 to 5,000 ppm
Accuracy < 999 ppm: ±40 ppm
>1,000 ppm: ±5% Rdg 
Resolution 1 ppm
General Specifications
Response Time 1 sec
Display Triple LCD display
Backlit Display Yes
Dew Point / Wet Bulb Calculation Yes
Data Hold Yes
Min, Max and Avg Functions Yes
CO2 Short Term Exposure Limit (STEL) Yes (15 mins)
CO2 Time Weighted Average (TWA) Yes (8 hours)
Alarm Yes (audible)
Auto Shut-off Yes (after 20 mins/off)
Low Battery Indicator Yes
Power Supply 4 AA Batteries
Battery Life Approx. 24 hours (continuous use)
Product Certifications CE
Operating Temperature 14 to 122°F (-10 to 50°C)
Storage Temperature 14 to 140°F (-10 to 60°C)
Operating Humidity Range 10 to 85%
Dimensions 7.9 x 2.7 x 2.3" (200 x 70 x 57 mm)
Weight 6.7 oz (190g)

What's included with the REED R9900

  • Indoor Air Quality Meter
  • Batteries
  • Hard Carrying Case

Ideal Applications for the REED R9900

Environmental Monitoring in:

  • Schools
  • Office buildings
  • Greenhouses
  • Factories
  • Hotels
  • Hospitals
  • Areas where high levels of carbon dioxide are generated

Click on a category to view a selection of compatible accessories with the REED R9900 Indoor Air Quality Meter.

REED CA-52A Small Soft Carrying Case

Model: CA-52A

Features a main instrument compartment and a side pouch for accessories.

REED R9933 Humidity Calibration Standard, 33%

Model: R9933

For use with REED R6001, R6200, SD-3007, R9900 and 8706.

REED R9975 Humidity Calibration Standard, 75%

Model: R9975

For use with REED R6001, R6200, SD-3007, R9900 and 8706.

REED R9980 Humidity Calibration Kit (33% and 75%)

Model: R9980

Kit includes the R9933 (Humidity Calibration Standard, 33%) and R9975 (Humidity Calibration Standard, 75%). For use with REED R6001, R6200, SD-3007, R9900 and 8706.

Holiday Season Savings with REED on the R8500, R6018, R5044, SD-9901, and the R9900
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When you purchase a REED product it comes included with a one year warranty. We back our products.