Honeywell CRIR E1
A commercial single-channel NDIR CO₂ sensor designed for indoor air quality and ventilation applications, with UART/Modbus communication and automatic baseline correction.
Key Specifications
Product Positioning
CRIR E1 is designed for normal IAQ applications and incorporates Automatic Baseline Correction to support long-term stability in occupied-space monitoring.
Official Resources
Specifications on this page are based on current Honeywell manufacturer documentation. Verify the latest datasheet and user guide before integration or purchasing decisions.
View Honeywell CRIR Official PageAirAlign is an independent informational resource and is not affiliated with Honeywell. Manufacturer documentation remains authoritative.
Honeywell CRIR E1 — economy NDIR with greater CO₂ uncertainty — engineering selection and model documentation
The published manufacturer values below are bounded to their orderable range, test conditions and actual interface, not general guarantees about every relative in the same sensor family.
| Parameter | Manufacturer evidence | Engineering boundary |
|---|---|---|
| Measured gas | Single-channel infrared NDIR carbon dioxide | Not a VOC-estimated eCO₂ output. |
| E1 accuracy grade | ±(50 ppm +5% of reading) | At 1,000 ppm approximate combined nominal error ±100 ppm, larger than M1. |
| M1 comparison | M1 ±(40 ppm +3% of reading) | For tight ventilation thresholds, evaluate absolute error at operating setpoint. |
| E1 range | 400–2,000 ppm standard; up to 5,000 ppm extended on existing order specification | Higher 10k ppm extended value appears for M1, not generic E1. |
| Digital data | UART/Modbus protocol, ~4-second update in original technical content | Physical UART should not be connected as native industrial 2-wire RS485. |
| Power and environment | 4.5–5.5 V; 300mA emission peak/~30mA average; 0–50°C and noncondensing indoor RH | Peak is critical to Wi-Fi battery nodes and regulator drop. |
| Calibration | ABC automatically targets 400ppm minimum over adjustable period | A permanently occupied hospital/process room could require a different calibration strategy. |
| Current OEM documents | Honeywell lists separate February 2026 E1 datasheet and user guide | Select the purchased article’s datasheet, not M1 pin/accuracy tables. |
System integration and calibration
E1 can be an economical indoor demand-control CO₂ module, but its percent-of-reading and fixed ppm error make it less suitable for certain stringent reference targets than CRIR M1. As with other ABC-calibrated single-channel infrared sensors, repeated outdoor-level exposure must be credible in the installed location. Alarm/ventilation thresholds should include absolute uncertainty at 1,000–2,000ppm. Source version labels, UART baud/configuration, pullups, reset timing and measurement-ready status should be commissioned on the real hardware. Finished fire/gas safety approval is outside this component listing.
Source and exact-order documentation: Original manufacturer catalogue, page and/or technical data sheet. Any version- or test-bound claim must be checked against the supplied production label before procurement.
AirAlign model-specific technical editorial update · 25 October 2026. These OEM values are not independently calibrated, certified, or evidence of active supplier stock.