一氧化碳氣體監測器評估

Evaluation of Carbon Monoxide Gas Monitors

本研究計畫藉由評估三種常用廠牌的一氧化碳氣體監測器，探討此三台一氧化碳氣體監測器的基本性能如何，以及若外界環境發生變化時，是否會造成監測器讀值的改變，以期增進對市售一氧化碳氣體監測器產品性能的了解。此三台監測器包括一台固定式（Sieger）及兩台攜帶式儀器（Drager及Quest），感測元件的設計應用原理皆為電化學式。評估項目包括：原廠校正準確性、溫機時間、感應時間、警報時間、線性關係、電壓變化影響、濕度效應、溫度效應、溫度變化影響、零點飄移、全幅飄移、短期再現性及長期再現性。在基本性能測試方面，三台監測器之中以Drager表現較為優異，對一氧化碳感應極為迅速而且無零點或全幅飄移現象。在受外界環境影響程度方面，以Quest監測器較為理想，其讀值受濕度、溫度及電壓變化等因素影響最不明顯。以所評估的三台監測器而言，溫度是影響讀值的最重要外在條件，35°C （5〜40°C ）的溫度變化對於三台監測器均有程度不一的影響。根據這些評估結果，在選擇監測器時應先對監測器本身的應用限制有所了解，方能達到監測器之使用目的。

This study is carried to evaluate and compare performances of three CO monitors made by different manufactures, including a stationary monitor obtained from Sieger Ltd. and two portable monitors produced by Dragerwerk AG and Quest Tech., respectively. The detection principle of these three monitors is the electrochemical method. The items studied include accuracy of original calibration, warm-up time, response time, alarm time, linearity, voltage effect, humidity effect, temperature effect, effect of temperature variation, zero drift, span drift, short-term reproducibility, and long-term reproducibility. Based on the experimental results, Dragerwerk CO monitor is found to be the most reliable one among the CO monitors evaluated regarding to individual characteristics. It responded to CO promptly and no obvious zero or span drifts were observed. On the other hand, Quest monitor is least affected by voltage, ambient humidity, and temperature. For these three monitors, temperature is probably the most important external factor which has noticeable impact on instrument readings. The results showed that gas monitors often have their own application limitations, one should fully realize this phenomena prior to field use.