テープ式吸収率計の開発と黒色純炭素連続測定への適用

抄録

Using tape type filter, an absorption photometer suitable for continuous absorptioncoefficient monitoring in remote area and black carbon (BC) monitoring in urban area was developed. This instrument is equipped with two fiber optic sensors, monitoring reflected light from aerosolcollecting spot and non-collecting part of the filter. The latter signal was used as a reference tocorrect the shift of the sensor sensitivity caused by temperature fluctuations. Collection spot was automaticallychanged when the signal from the spot decreased below a threshold value. Measurements were conductedin Sapporo in October and November 2003 (period-I), and February and March 2004 (period-II) toevaluate and characterize the instrument. The good correlation between absorption coefficients measure by the instrument and EC concentrations measured by thermal method was found (R²=0.961 at period-I and R²=0.797 at period-II). One-hour BC concentrations calculated based on the regressions rangedfrom 0.5 to 7.8μg/m³. The instrument was found to be easy to use and had sufficient sensitivity to beuseful in atmospheric monitoring.