本研究已成功地整合半導體感測器、掌上型微處理機、顯示器、鍵盤及警報器等技術開發出一套可攜帶直讀式氣體偵測器(Personal Hazard Air Monitor, PHAM)，使國內未來在做環境測定時不至受到購買進口儀器的限制；並可針對研究的性質加以改良偵測器的性能並提供技術支援，可幫助國內廠商建立本土化氣體偵測器開發技術，並對以後從事環境測定及暴露評估的研究相信有很大的助益。 PHAM之尺寸為130´100´32mm，重量僅200g，其系統之模組包括微電腦處理機、半導體型氣體感測器、LCD顯示器、12鍵之數字鍵盤及聲音及燈光警報器。PHAM可即時顯示目前濃度值、STEL濃度值、最高濃度值、TWA濃度值，並可將資料儲存於內建之記憶體中供使用者下載進行分析，且具有濃度警報功能，電力供應使用鎳氫充電電池可持續偵測長達13小時。性能測試的結果顯示，PHAM之主要噪訊來源為感測器，其背景噪訊非常低，偵測極限達0.095V，以酒精為例，表示可量測之最低酒精濃度為1 ppm。PHAM之反應時間小於30sec，可符合工廠環境測定之所需。實驗室模擬測試的結果顯示感測器之校正曲線會有偏移的現象，造成實際量測時之準確度不高。在實場採樣中發現感測器會受其他物質之干擾使量測值誤差過大，故在實場應用實仍有其限制。未來應考慮使用具選擇性之感測器以提升氣體偵測器之性能。 A personal hazardous air monitor (PHAM) have been developed in this study. The PHAM is consisted of a semiconductor gas sensor, a multifunctional microprocessor, a LCD monitor, a keyboard and an alarm. The dimension of the PHAM is 130´100´32mm, and it’s weight is only 200g (600g when a battery packis included). The PHAM can read instant concentrations, STEL concentrations, TWA concentrations, peak concentrations, signal voltages and sampling durations. The battery life is about 13 hours. Monitoring data can be stored in the build-in memory and can be downloaded to PC for further analysis. The PHAM has very low baseline noise based on the laboratory test results. The limit of detection (LOD) of the PHAM is around 1 ppm if the target compound is ethanol. The laboratory test showed that the system can easily monitor the concentration changes when the volunteer moved from room to room. Although, the system has many characteristics, further improvements in sensors can make the system more stable.
