铝熔体在线式测氢仪准确性问题研究

Study on accuracy of on-line hydrogen measuring instrument for melt aluminum

以实证方式对目前国内已广泛使用的铝熔体在线式测氢仪的准确性问题进行了研究。其一,对符合西华特(Sievert)定律的测氢仪,如ALSCAN、HDA-IV、ELH-IV测氢仪,进行了标气验证,发现ELH-IV测氢仪与ALSCAN、HDA-IV测氢仪对西华特定律中S值的取值有较大差异;对仪器的标准曲线覆盖范围进行了讨论。其二,在数家工厂现场安排了HDA-IV与ALSCAN测氢仪的对比测试并对大量ALSCAN测氢仪测量数据进行了分析,发现ALSCAN新老仪器之间的测量数据曲线有较大差异,证明了装老泵的ALSCAN测氢仪有污染源问题而导致测量值偏高。其三,对测氢探头进行了必要的评价。最后,简要介绍了HDA-IV测氢仪。

The accuracy of on line hydrogen measuring instruments being used widely in China has been investigated. The ALSCAN, HDA-IV, ELH-IV hydrogen measuring instruments have been checked by calibrating gas. All the above mentioned instruments are work- ing at Sievert law. From the checking result we can see that the S values of Sievert-law are much different among ELH-IV, ALSCAN and HDA-IV. The overlap coverage to the standard curve of the instruments has been appraised. The HDA-IV and ALSCAN instruments have been brought to several casting houses for contrast detecting, and all the detecting valuse have been analyzed. The results show that among the checked value curves from new and old ALSCAN instruments exist considerable differences, because the old ALSCAN instruments are working with old pumps which were polluted and the detecting values would be higher due to the pollution. The hydrogen detecting probes have been evaluated. The HDA-IV hydrogen measuring instrument has been introduced as well.