K-33 ELG 1% CO2 + RH/T Data Logging Sensor

K-33 ELG 1% CO2 + RH/T Data Logging Sensor
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The K-33 ELG (environmental logger) is designed to measure up to 10,000ppm (1%) carbon dioxide, temperature, and relative humidity in remote locations. Because of its ultra-low power requirements, it can “wake up”, take a sample, store the data in memory, and go back to sleep. Using battery power only, the sensor can be placed in the field for days or weeks at a time.

With multiple input and output options and support for I2C and Modbus protocols over TTL levels, the K-33 ELG combines the quality of our dual infrared NDIR sensor technology with configuration options to satisfy even the most critical applications.

co2 sensor sdk



  • CO2 Measurement: non-dispersive infrared (NDIR)
  • CO2 Range: 0 – 10,000 ppm
  • CO2 Accuracy: ± 30ppm ± 3% of measured value
  • Temperature Range: -40 to 60C
  • Temperature Accuracy: ± 0.4C at 25C
  • Relative Humidity Range: 0-100% RH non condensing
  • Relative Humidity Accuracy: ± 3% RH
  • Sampling Method: diffusion
  • Data logging: 30 seconds to 18 hours sample interval for CO2, RH & T
  • Optional: Support for real-time measurement with software
  • Memory: 5,400 log entries maximum, includes timestamp, co2, temp, RH. 1 additional analog input to the log available
  • Sensor Life Expectancy: > 15 years
  • Maintenance Interval: no maintenance required

Electrical / Mechanical:

  • Power Input: 6-14 VDC max rating, stabilized to within 10%
  • Dimensions: 2.0 × 2.25 × 0.5 inches

90 days

Datasheet Data Sheet & Manual (pdf)

Datasheet Configuration Guide (pdf)

Communication Protocols Manuals (zip)

Sensor Calibration Procedure (pdf)