TandD TR-76Ui

  • Wide CO2 measurement range of up to 5,000 ppm
  • Logging capacity of 8,000 data sets
  • View measurements on one easy-to-read graph
  • Possible to save data as text for use with common spreadsheet software
  • Transmit recorded data to PC via USB connection
  • Temperature measurement range of 0 to 45°C
  • Humidity measurement range of 10 to 90% RH
  • Recording intervals from 1 second up to 60 minutes
  • Dimensions: H96 x W66 x D46 mm
  • Included batteries and sensor



The TR-76Ui USB Temperature Humidity CO2 Data Logger is a three-channel logger designed to simultaneously measure and record carbon dioxide concentration, temperature and humidity. Making atmospheric pressure settings for the measurement location ensures more stable and accurate Carbon Dioxide measurements. The supplied software enables the user to download data recorded by TR-76Ui to PC via USB connection, whereby data from all three channels can be simultaneously viewed in graph or table form.

The product is an all-in-one package that includes the data logger unit, sensors and software. We offer two types of packages with different temperature/humidity sensors depending on your required measurement range and accuracy needs.

By using a Data Collector TR-57DCi (sold separately), it is possible to collect recorded data from the TR-76Ui via infrared communication and immediately check the collected data on the spot.

This versatile data logger can be used in a wide range of applications from personal to business use; for measurements of home environment, CO2 measurements in offices and other buildings, and/or energy-saving measures such as ventilation and air conditioning controls.

View the TR-7x Product Brochure (PDF) or the TR-7wf/nw Series Overview Video.


Product TR-76Ui TR-76Ui-H
Temperature/Humidity Sensor (External) THA-3001 HHA-3151(High-Precision Type)
Thermistor Polymer Resistance Platinum Resistance Electrostatic Capacitance
Measurement Channels Temperature 1ch Humidity 1ch Temperature 1ch Humidity 1ch
Units of Measurement °C, °F %RH °C, °F %RH
Measurement Range 0 to 55°C 10 to 95%RH -30 to 80°C 0 to 99%RH
(Note: Operating environment of the TR-76Ui itself is 0 to 45°C, 90 %RH or less)
Accuracy ±0.5°C ±5%RH

(at 25°C, 50%RH)

±0.3°C (at 10 to 40°C)

±0.5°C (at all other temperatures)

±2.5%RH (at 25°C, 10 to 85%RH)

±4.0%RH (at 25°C, 0 to 10% or 85 to 99%RH)

At temperatures other than 25°C and 0°C, add ±0.1%RH per degree of difference from 25.

Humidity Hysteresis: ±1.5%RH or lower (*1)

Measurement Resolution 0.1 °C 1 %RH 0.1 °C 0.1 %RH
Response Time (90%) Approx. 7 min. Approx. 7 min. Approx. 20 sec.
CO2 Sensor (Internal)
Sensor NDIR
Measurement Channels CO2 Concentration 1ch
Units of Measurement ppm
Measurement Range 0 to 9,999 ppm
Accuracy ±(50 ppm + 5 % of reading) (*2) (at 5,000 ppm or less)
Measurement Resolution Minimum of 1 ppm
Response Time (90%) Approx. 15 min.
Logging Capacity 8,000 data sets (One data set consists of readings for CO2 concentration, Temperature and Humidity measurements.)
Recording Interval Select from 15 choices: 1, 2, 5, 10, 15, 20, 30 sec. or 1, 2, 5, 10, 15, 20, 30, 60 min.
Recording Mode Endless (Overwrite oldest data when capacity is full) or One Time (Stop recording when capacity is full)
LCD Display Items Measurements, Battery Level, etc.

– Measurements: CO2 concentration, Temperature or Humidity (fixed or alternating display)

Communication Interfaces USB Communication, Serial Communication (RS-232C) (*3), Infrared Communication (IrPHY 1.2 low power) (*4)
Communication Time Downloading time for one unit at full capacity

– Via USB communication: approx. 45 sec.

– Via infrared communication: approx. 60 to 80 sec.

External Alarm Terminal Output Terminal: Open Drain Output (Voltage when OFF: DC less than 30V / Current when ON: less than 0.1A / Resistance when ON: about 15Ω)
Power AC Adaptor (AD-0638 or AD-0638-C), AA Alkaline Battery (LR6) x 4
Battery Life Approx. 2 days (batteries only without AC adaptor) (*5)
Dimensions H 96 mm x W 66 mm x D 46 mm (excluding protrusions and sensor)
Weight 214 g (including batteries, excluding sensor)
Operating Environment Temperature: 0 to 45 °C, Humidity: 90 %RH or less (no condensation)
Accessories AA alkaline battery (LR6) x 4, AC Adaptor (AD-0638 or AD-0638-C), USB Communication Cable (US-15C), Temperature/Humidity Sensor (THA-3001 or HHA-3151), Software (CD-ROM), User’s Manual Set (Warranty Included)
  • *1: When used in environments where temperature and humidity are over the values of 50°C 75%, 60°C 50%, 70°C 35%, and 80°C 25%, sensor hysteresis may fluctuate by values greater than ±1.5%RH. Under certain circumstances, it may take some time to return to normal measurement capability.
  • *2: Stated value is the measurement accuracy of the CO2 sensor when Auto Calibration is operating properly. A change in atmospheric pressure directly influences the reading of CO2, which can cause measurement errors; a decrease in pressure by 10hPa results in a relative decrease in CO2 by 1.6%. In such a case, we recommend carrying out the “Atmospheric Pressure Correction” function found in CO2 Recorder for Windows.
  • *3: Customers wishing to write their own software, please contact your local distributor for the serial communications protocol specifications. (Note: Optional serial communication cable TR-07C is also required.)
  • *4: If you wish to use infrared communication to download recorded data, it is necessary to purchase the Data Collector TR-57DCi (sold separately).
  • *5: Battery life varies depending upon the ambient temperature in which it is used, the recording interval, the frequency of communication, and the battery performance. All estimates are based on operations carried out with a new battery and are in no way a guarantee of actual battery life. Battery life may be shortened if the unit is used under inverter type fluorescent lighting.


TR-76Ui is a three-channel data logger designed to simultaneously measure and record carbon dioxide concentration, temperature and humidity. It is capable of measuring CO2 concentrations up to 5,000 ppm.

Reference Data:About CO2 Levels and their Possible Effects

*This unit is not designed for use in preventing health problems.

Simultaneously View Three Measurement Items in one Easy-to-Read Graph
The recorded data downloaded from TR-76Ui units is read in the Multi-Scale Graph where the data of three items, CO2 concentration, temperature and humidity, can be simultaneously viewed in graph or list form, as well as, printed out.

It is also possible from the graph window to calculate and view the highest, lowest and average readings for a desired range (time period).

Large Logging Capacity: 8,000 Data Sets
One data set consists of readings for all three channels: CO2 concentration, temperature, and humidity. There are 15 recording intervals (1 seconds to 60 minutes) to select from. At the longest recording interval of 60 minutes, recording can continue consecutively for one year.

Atmospheric Pressure Correction Function
This function enables the TR-76Ui software to calculate the atmospheric pressure from the altitude at the measurement location. By using a correction factor for the atmospheric pressure at the measurement location, more reliable CO2 concentration measurements can be achieved.

View Current Readings for all Three Channels on LCD
CO2 concentration, temperature, and humidity measurements are shown on the large easy-to-read LCD screen.

While CO2 measurement is always displayed, the display pattern for temperature and humidity can be selected from an alternating display of two or fixed display of either one.

Manage Recorded Data with Common Spreadsheet Software
By using the Multi-Scale Graph, data downloaded from the TR-76Ui can be saved into text format for use with common spreadsheet software.

Transmit Recorded Data to PC via USB Connection
It is possible to connect a TR-76Ui unit directly to your computer with a USB cable. Moreover, it is possible to gather current readings from the TR-76Ui connected to your computer and view those readings in the computer display.

Easy Data Collection on the Spot: No Computer Necessary (TR-57DCi)
By using our Data Collector TR-57DCi (sold separately), it is possible to gather and check recorded data on the spot.

* TR-76Ui support on the TR-57DCi is planned for release at the end of February 2012.

Warning Function with Output Contact
When a set upper or lower limit has been exceeded, it is possible to use the provided output contact on the unit to issue a warning. This function can be used in conjunction with external devices such as a ventilation device.

* To connect to an external device, please use a JST Connector PAP-04V-S.