Senva CT1O-G3D Outdoor CO2 Sensor, LCD, 10K ohm Type 3 thermistor with 11K ohm shunt

The Senva CT1O-G3D is a CT1O outside-air CO2 sensor with an NDIR sensing element, a built-in heater, and an LCD display. This configuration includes a 10K ohm Type 3 thermistor with 11K ohm shunt as its temperature sensing option; it is not the temperature-transmitter version.

CO2 output scaling is 0-2000 ppm by default, with selectable 0-5000 ppm and 0-10000 ppm ranges. Analog outputs are 4-20 mA and selectable 0-5 V/0-10 V. The integrated programmable normally open solid-state setpoint relay is rated 1 A at 30 VAC/DC. The LCD provides a field calibration and setup menu.

Specified CO2 accuracy is +/- (30 ppm + 3% of reading) at 400-2000 ppm and +/- (50 ppm + 5% of reading) at 2000-5000 ppm, at -10 to 50 degrees C and 0-85% RH. These are accuracy conditions, not an overall operating-temperature rating. Supply requirements are 12-30 VDC, 50 mA maximum, or 24 VAC, 100 mA maximum; 10 V output requires 15-30 VDC or 24 VAC. A dedicated transformer is recommended because one side of the transformer secondary is connected to signal common.

The enclosure is rated NEMA 1. The manufacturer specifies adding drain holes to the enclosure bottom to achieve NEMA 3R; do not assume the unmodified enclosure has that rating.