The three-channel data logger TR-76Ui-H simultaneously measures and record CO2 concentration, temperature and humidity. It achieves a temperature measurement accuracy of ±0.3°C between 10° and 40°C. The accuracy is ±0.5°C at all other temperatures. The overall range is -30° to 80°C. Automatic atmospheric pressure adjustment for the measurement location ensures more stable and accurate CO2 measurements. The unit has a CO2 range up to 9,999 ppm with accuracy of ±(50 ppm + 5% of reading) (at 5,000 ppm or less). Humidity measurements range from 0 to 99% with accuracy of ±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. It has a capacity to store up to 8,000 data sets and is supplied with software which enables the user to download recorded data to a PC via USB connection, whereby data from all three channels can be simultaneously viewed in graph or table form.