常用直讀式粉塵計之性能評估

Evaluation of Commonly Used Direct Reading Dust Monitors

本研究利用一個粉塵室測試了三種不同的直讀式粉塵計：GCA MINIRAM PDM-3，TSI 8510及Sibata PCD-1，對不同粉塵的測值反應，並與標準濃度值相比較，期能進一步了解這些粉塵計的適用情形。同時本研究也在工作場所對此三種粉塵計的性能作實地的測試，以便了解現場和實驗室測值的差異，使研究結果更具體有用。本研究發現GCA MINIRAM PDM-3雖然對於不同的粉塵會有一些不同的測值反應，但是對各類粉塵的總粉塵濃度Ctot的準確度均可在±10～15％之間。TSI8510對細亞利桑納粉塵的可呼吸粉塵測值Cresp偏低很多，在低Cresp時對石英及碳粉塵的測值比較正確，但當Cresp>6.0 mg/m3時對石英粉塵的測值會呈偏低的現象，對於碳粉塵測值的正確性則就沒有什麼影響。Sibata PCD-1的校正k值 （k=實際值／儀器讀值）對石英及細亞利桑納粉塵而言，均十分接近6.0，且和粉塵濃度無關；但是對碳粉塵而言，只有當Ctot>3.0 mg/m3時，k值才會維持在15左右的定值。在鑄造廠及電鍍廠的現場測試結果發現，GCA MINIRAM PDM-3和TSI 8510之測值和標準值相 較，在高濃度時都有嚴重偏低的情形，在低濃度時則比較接近。而Sibata PCD-1的k值對不同作業場所都可接近6.0，和在實驗室中Sibata PCD-1對石英及細亞利桑納粉塵的實驗k值相同。本研究在現場也針對SKC及10-mm尼龍旋風器作測試，結果發現這兩種個人採樣器在新的採樣流量之下（SKC:2.2 L/min及10-mm: 1.3 L/min），均能夠測到十分正確的新ACGIH規範下的可呼吸性粉塵濃度。

This study used a dust chamber to test the response of three direct reading dust monitors : GCA MINIRAM PDM-3, TSI 8510 and Sibata PCD-1, to different dust particles. The results were compared with standard concentrations in order to understand the applicability of these monitors. The experiment was also conducted at different workplaces to see if there were any differences between laboratory and field test data. It is hoped that results of this study be practical and useful. It is found in this study that the accuracy of GCA MINIRAM PDM-3 in regard to total dust concentration is within EMBED Equation 10~15%, independent of dust materials. The TSI 8510 underestimates the concentration of Arizona road dusts seriously, it is more accurate for quartz and carbon dusts at low Cresp. But when Cresp > 6.0 mg/m3, it will underestimate quartz dust concentration while it remains accurate for carbon dusts. The calibration constant of the Sibata PCD-1 is very close to 6.0 for both quartz and Arizona road dusts and is independent of dust concentrations. However, the k value (k = actual concentration/indicated concentration)for carbon particles remains constant at 15 only when the total dust concentration is greater than 3.0 mg/m3. In the field study at foundry and electroplating plants, it is found that both the GCA MINIRAM PDM-3 and TSI 8510 underestimate the dust concentration to a great extent when the dust concentration is high. These two instruments are more accurate at low dust concentrations. The calibration constant k is close to 6.0 for the Sibata PCD-1, which is the same as found in the laboratory for both quartz and Arizona road dusts. Finally in the field study, the SKC and 10-mm cyclones are found to sample respirable dust accurately according to the new ACGIH criteria at the flow rate of 2.2 and 1.3 L/min respectively.