Sensors That Make Buildings Smart!
AirTest CO2 Control Brochure
The Free AirTest CO2 Ventilation Calculator Tool
Suggested CO2 Sequence Of Operation
CO2 In School Classrooms
CO2 Reference Library
Reduce Over Ventilation And
Energy Waste with CO2
Background on CO2 for Ventilation Control
Explanation of CO2 sensor self calibration for TR9220 and TR9290
Why" Length Matters" for CO2 meansurement (TR9220, TR9290)
Technical background on CO2 DCV
Using CO2 to measure combustion fumes
Using CO2 to control smoking in hospitality venues
Assessing buildings for CO2 retrofit
CO & energy savings case studies
AirTest CO2 energy analysis software
AirTest Training Center

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Model TR9290 Model TR9290 Model TR9291
Wall Mount Wall Mount With Display In-Duct / In-Unit Mount
Model TR9294 Model TR9294 Model TR9292
Wall Mount Wall Mount With Display Duct Probe Mount
LonWorks® and BacNet® Versions Now Available LonWorks® and BacNet® Versions Now Available LonWorks® and BacNet® Versions Now Available
Model TR9292 Model TR9293 Model TR9293
Duct Probe Mount
With Display
Splash Resistant
Wall Mount
Splash Resistant
Wall Mount With Display
LonWorks® and BacNet® Versions Now Available LonWorks® and BacNet® Versions Now Available LonWorks® and BacNet® Versions Now Available


  • Commercial buildings
  • Schools & universities
  • Retail
  • Theaters, auditoriums, gyms, churches
  • Hospitality venues


Key Features

  • Built in self calibration feature results in zero maintenance over sensor rated life (15 years)
  • Background calibration feature also automatically considers outside concentrations without an outside sensor (see "Background On Sensor Self Calibation" to left)
  • Utilizes patented gold plated optical sensing element with 4.7 inch extendedmeasurement path length for maximum stability & resolution. (see "Length Matters" to left)
  • ISO-9001 manufactured for quality
  • Now also available with LonWorks® communication capability as a LonMark® Certified product.
  • Now BACnet® Communicating


Related Products

  • The PT9250 Handheld CO2 monitor can be used in comissioning CO2 sensors and in characterizing ventilation rates. It can also be used to estimate potential energy savings in CO2 retrofits (see "Assessing Buildings for CO2 Retrofits" to left).

Model TR9290 Family

CO2 Transmitter

  • Measures: 0-2,000 ppm CO2, Factory adjustable to 10,000 ppm
  • Accuracy: ± 30 ppm + 3% of reading
  • Power: 24 VAC
  • CO2 output: 0-10 V, 0-5 V, 4-20mA
  • Maintenance free for 15 years or more
  • Also available as a LonMark Certified Product for TR9292, TR9293 and TR9294 models
  • Now BACnet® Communicating

Datasheet Manual Engineering Spec
BACnet Application Guide
LonMark® Certified Catalog Listing
LonWorks XIF/DRF Files


Order Guide

Model Number Output Display
TR92901 - Wall 3" X 3" A - 0-5V & 4-20mA _ - No Display
TR92911 - In Duct B - 0-10V & 4-20mA L - LCD Display3
TR9292 - Duct Probe Lon - LonWorks®2
TR9293 - Splash Resistant Bac - BACnet MS/TP
TR9294 - Wall 3.25" X 5"

1 - LonWorks® & BACnet® versions not available

2 - LonWorks® Certified

3 - Display not available on TR9291 In Duct

Published: February 16, 2004 Last Updated: April 15, 2013