LI-COR ENVIRONMENTAL · AIR QUALITY MONITORS & GAS DETECTORS

LI-COR LI-7820 N₂O/H₂O Trace Gas Analyzer

LI-COR LI-7820 N2O H2O trace gas analyzer

Research-grade optical trace-gas analyzer for environmental monitoring; a complete instrument rather than a raw sensor.

Technical details

Measured gases	N₂O and H₂O
Technology	OF-CEAS
N₂O range	0–100 ppm
N₂O precision	0.40 ppb at 330 ppb with 1 s averaging
Use	Soil flux and environmental research

Official technical source

Manufacturer model information →

For engineering use, confirm the exact variant, manufacturer datasheet and instrument-level compliance.

LI-7820 — N₂O soil flux and water interference

LI-COR LI-7820 is a finished optical analyzer for N₂O and H₂O, suitable for environmental research rather than a simple single-board gas sensor. The cited 0.40 ppb precision at 330 ppb with 1-second averaging applies to specified test conditions, not every field sampling setup. For soil-flux work, validate chamber leakage, sample flow, moisture compensation and concentration calibration independently. Preserve timestamp and instrument diagnostics when interpreting long-term low-concentration measurements.

LI-7820 — OF-CEAS N₂O/H₂O research-grade trace analyzer — original technical reference

Model-specific measurement and electrical figures, output options and their source limitations.

Measured feature	Maker data	Practical engineering implications
Spectroscopic technique	Optical Feedback–Cavity Enhanced Absorption Spectroscopy (OF-CEAS)	This is not a generic NDIR low-cost N₂O gas module.
Nitrous oxide range	0–100 ppm N₂O	ppm-scale upper measurement and ppb precision are separate specifications.
N₂O precision at 330 ppb	1σ 0.40 ppb with 1 s average; 0.20 ppb with 5 s average	Precision is statistical repeatability under controlled conditions, not overall field absolute accuracy.
Response	T10–T90 ≤2 s standard flow, ≤3 s high-altitude configuration	Chamber/pump tubing transport and sample manifold may slow the installed workflow.
Water vapour	0–60,000 ppm H₂O; 45 ppm precision at 10k H₂O with 1 s average	Gas concentration corrections need distinction between wet/dry mole fractions.
Drift	Manufacturer N₂O maximum drift <1 ppb per 24h	Long-term field use needs zero/span QA with site environmental exposure.
Operating power	22 W steady at 25 °C; up to 65 W warmup without charging and 100 W while charging	Power design and field UPS must account for transient consumption.
Communication / runtime	Ethernet/Wi-Fi; typical eight hours using two batteries	Wi-Fi can be market-dependent; network outage must not erase locally buffered records.
Ambient	−25 to +45 °C, 0–85%RH noncondensing; atmospheric operating pressure variants	High-altitude versions have different pressure acceptance limits.

System selection and verification

For chamber soil emissions, LI-7820 samples N₂O and H₂O to support flux slope calculations. Pairing with LI-7810 can add methane/CO₂ but does not make LI-7820 itself a direct methane instrument. A 0.20 ppb (5 s) precision claim is not a guarantee of that accuracy for field emission rate or cross-instrument comparison; chamber leakage, timing and soil pressure flux models matter. Document the optical path, pump/flow setting, actual electrical pin set and power headroom, calibration drift and data traceability.

Primary official specification: Model manufacturer technical documentation. Order suffixes, current revisions, traceable calibration and certifications are subject to final confirmation.

AirAlign manufacturer-specific editorial enhancement · 25 October 2026. Not independent source calibration, site regulatory signoff or finished-safety-instrument certification.