The document discusses LI-COR's trace gas analyzer platform and its applications. The platform uses optical feedback cavity enhanced absorption spectroscopy and can measure methane, carbon dioxide, and nitrous oxide. It is designed for flexibility in field research. Applications discussed include measuring soil gas fluxes, long-term atmospheric monitoring, urban and mobile emission monitoring, measuring pCO2 in seawater, and profiling gas storage fluxes.

1. LI-COR Trace Gas Analyzers - Applications for
Measurements of Methane, Carbon Dioxide, and
Nitrous Oxide
Graham Leggett, Principal Scientist, LI-COR

2. Overview
•LI-COR Biosciences
•Trace Gas Analyzer platform
• Platform and model-specific specifications
• N2O measurement performance
•Trace Gas Analyzer applications
• Soil flux
• Long-term atmospheric measurements
• Urban and mobile monitoring
• pCO2 measurements
• Storage flux - Profiling

3. LI-COR Biosciences
Environmental Biotechnology

4. Trace Gas Analyzer Platform
Design features, measurement principle, performance

5. • Multiple patented technologies which balance
performance and design
• Utilize Optical Feedback – Cavity Enhanced
Absorption Spectroscopy (OF-CEAS)
• Maintain performance at a lower cost
• Performance in the field comparable with lab-
based analyzers, but with a design allowing
more flexibility to meet research needs today
Trace Gas Analyzer Platform
Supported in part under the DOE/ARPA-E, MONITOR program - The initial principles and some portions of the new technology presented herein were developed in part based on the grant from
the MONITOR Program by the U.S. Department of Energy Advanced Research Projects Agency - Energy (ARPA-E), under award number DE-AR0000537.

6. Trace Gas Analyzer Platform

7. • Temperature range: -25°C to 45°C
• Operating pressure: 70 to 110 kPa
• Weight: 10.5 kg with batteries
• Internal Data Storage: ~3 month
• Measurement rate: 1 sample per second
• Flow rate: 280 sccm (optional 70 sccm)
General Specifications

8. LI-7810, LI-7815 and LI-7820
Specification LI-7810 LI-7815 LI-7820
Gases measured CH4/CO2/H2O CO2/H2O N2O/H2O
Primary, high-precision analyte CH4 CO2 N2O
Concentration range 0-100 ppm 0-10,000 ppm 0-100 ppm
Precision (1σ, 1 second
averaging)
0.6 ppb 0.1 ppm 0.4 ppb
Precision (1σ, 5 second
averaging)
0.25 ppb 0.04 ppm 0.2 ppb
Drift (24 hours) <1 ppb <0.2 ppm <1 ppb
Response time (T10-T90) <2 seconds <2 seconds <2 seconds

9. LI-7820 Allan Deviation

10. Trace Gas Analyzer Applications
Survey and long-term measurements, flux data processing

11. Soil Flux Chamber Measurements – Introduction

12. Survey measurements
Soil Flux Measurements – Survey and Long-Term
Long-term chamber measurements

13. LI-7820 Example Measurements (1-Year)

14. LI-7820 Example Measurements (1-Week)
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
9/20/19 9/21/19 9/22/19 9/23/19 9/24/19 9/25/19 9/26/19
FN2O
(nmol/m2s)
F_N2O_1 F_N2O_2 F_N2O_3 F_N2O_4
Thunderstorm (MDF) ~0.05 nmol m -2 s-1

15. Long-Term Atmospheric Measurements
Ambient CH4 Comparison between
LICOR LI-7810 and PICARRO G2401
(A) Mixing Ratios
(B) Difference
(C) Ratio
(A) Photographer Gavin Kelly. Copyright Colin O'Dowd. Reprint permission granted to LI-COR.

16. Urban and Mobile Monitoring
LI-850 – urban sensor
network
LI-7815 – mobile emissions
location and quantification

17. pCO2 Measurements
• System continuously samples
seawater as ship is sailing
• ‘Showerhead’ equilibrator
accelerates gas exchange
• Gas in equilibrator sent to LI-7815
for analysis
• 99 % response in 2-3 minutes
• Operational on commercial cargo
vessels

18. Storage Flux - Profiling

19. Summary
• Trace Gas Analyzer platform
• Trace Gas Analyzer applications
• Soil flux
• Long-term atmospheric measurements
• Urban and mobile monitoring
• pCO2 measurements
• Storage flux - Profiling

20. Thank you!
www.licor.com/env
graham.leggett@licor.com