Abstract

Authors

Yukio Yasuda , Yoshikazu Ohtani, Yasuko Mizoguchi, Tsuyoshi Nakamura3 and Hideyuki Miyahara

Year

2008

Title

Development of a CO₂ gas analyzer for monitoring soil CO₂ concentrations

Journal

Journal of Forest Research

Volume

13(5)

Page

320-325

DOI

doi:10.1007/s10310-008-0079-3

Keywords

CO₂ analyzer - CO₂ concentration - Field test - Response test - Soil gas

URL

.http://www.springerlink.com/content/9632680v00116781/

Abstract

Measurement of soil CO₂ concentrations is important for investigating the dynamics and diffusion of CO₂ in soil. In this study, we developed a small CO₂ analyzer for measuring in situ-soil CO₂ concentrations. The CO₂ analyzer consists of a module containing an infrared CO₂ gas sensor, a temperature sensor, and a relative humidity sensor. These sensors are installed in a protective box with an air vent, which is suitable for burying in the soil. The output response time of the CO₂ analyzer was 349 s, as evaluated from the phase lag after input of known CO₂ concentrations. This response time is short enough to measure soil CO₂ concentrations, because variations in concentration are slower than the response time of the analyzer. In a field test, we used the CO₂ analyzer to measure soil CO₂ concentrations at five depths (0 50 cm) over 2.5 months. While the CO₂ concentration generally increased with depth, the amplitude of the variation in CO₂ concentration decreased with depth. The phase lag of the variations in soil CO₂ concentration also increased with depth, as did soil temperature. The tests confirm that the CO₂ analyzer is applicable to continuous monitoring of soil CO₂ concentrations.

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