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1.
易江 《干旱环境监测》1996,10(2):110-112
燃煤(油)固定污染源二氧化硫排放总量监测(四)烟气采样器及其应用易江(中国环境监测总站100012)接1996,1O(1):45~487GM—100型、SGS一94型烟气采样器及其应用GM——100型、SGS—94型烟气采样器是吸收、消化国外先进技术...  相似文献   

2.
精密限流孔在恒温恒流大气采样器中使用的讨论刘忠林(山东临沂市环境监测站,临沂276001)由于现在生产的大气恒温恒流采样装置对采样系统中的负载及限流孔前的气温都不能测出,所以气态方程难以在实际工作中应用,必须在一定误差范围内进行修约:①一周时间内大气...  相似文献   

3.
(一)实验仪器:自动仪器采用美国TE公司的43型二氧化硫分析仪、化学法采样器,因当时尚无专用采样器,采用真空泵作动力、限流孔控制流量,用大口冷藏瓶盛水维持采样吸收液(TCM)8—12℃的温度.样品分析用721型分光光度计、盐酸副玫瑰苯胺法.(二)对比试验方法:采用两种监测方法各用两套仪器平行对比的方法.对比前先校正仪器.自动仪器校零校标.然后两套仪器平行测定空气中二氧化硫,使平行日平均浓度连续3天,每天相差不大于15%.化学法采样装置首先选择合乎要求的采样管,在装  相似文献   

4.
限流孔在恒温恒流大气采样器中的作用   总被引:1,自引:0,他引:1  
通过试验,验证了限流孔恒流是指限流孔前有负载时气体状态流量恒定,并应用气体方程推导出流量修正公式,找出影响限流孔流量变化的因素,根据对各影响因素的讨论,提出了对现生产使用的24h恒温恒流采样吕听改进建议。  相似文献   

5.
在查阅大量文献的基础上,分析总结了现有采样器的优缺点,并依据采集有代表性含油水样的理论要求,设计制作了一种独具特色而又科学适用的新型合油水样采样器。本采样器可用于采集含油水样和其它水样。  相似文献   

6.
目前我们常用的气体采样器的流量指示值往往因负载阻力大小、气压大小以及电机电源的电压大小的改变而与真实值有较大误差。本文认为,造成这种现象的主要原因是转子流量计本身的特性和采样器的构造设计不合理引起。理由如下: 目前我们使用的采样器,计量多采用转子流量计。转子流量计的流量公式为:  相似文献   

7.
采用分级撞击采样器(DPI)对燃煤电厂烟气颗粒物测定并分析,试验表明,PM10、PM2.5及PM1在湿除出口/烟囱入口的质量浓度分别为0.26 mg/m3~1.47 mg/m3、0.22 mg/m3~1.29 mg/m3、0.17 mg/m3~1.00 mg/m3。分析可知,除尘器后烟气颗粒物PM10中主要是PM2.5,而PM2.5~10占比低于35%;烟气经湿法脱硫后,PM2.5~10的比例进一步大幅降低,经湿式除尘器后,PM2.5~10的占比变化很小,而PM1~2.5的占比大幅降低。监测结果表明,湿式除尘器对烟气颗粒物的脱除效果优于湿法脱硫,而随着颗粒物粒径的减小,2种脱除设备的脱除效率均出现降低。  相似文献   

8.
大气全量多环芳烃采样器的研究   总被引:3,自引:0,他引:3  
设计并制作了可以采集大气中全量(态)多环芳烃的新型采样器。该采样器对多环芳烃的采集效率高、重复性好、操作方便,所使用的国产吸附剂吸附性能好,透气性强,便宜且易得。用该采样器在不同地区采集样品的数据有力地说明了不可忽视气态多环芳烃的污染。  相似文献   

9.
为了实现滤膜式PM2.5测量仪中挥发性颗粒物的连续补偿测量,根据挥发性颗粒物加热挥发、冷却凝结的物理特性,利用冷凝装置和串级冲击采样器原理,设计了双通道的挥发性颗粒物连续采样测量装置。按照采样粒径为10、5、2.5μm的颗粒物设计了3级冲击采样器,通过理论计算得到了采样器的孔径、孔数等相关参数;对采样器中采集的样品使用石英晶体微天平(QCM)直接测量,并采用加热清洗的方式结合双通道的设计实现挥发性颗粒物的连续采样测量。该装置不但可以应用于目前滤膜式颗粒物监测仪中的挥发性颗粒物补偿测量,使测量结果更加准确可靠;也可直接应用于挥发性颗粒物的测量分析。  相似文献   

10.
由于油在水中呈不均匀分布的特性,所以有关环境水体中油的采样工具,一直是环保部门关注的焦点。为此提出了“理想(或称假想)水柱”的概念,并依此设计出一种在环境监测工作中使用的便携式测水中油用采样器,适用于工业废水、生活污水及污染的地表水的采取。其特点是,一个底部可开闭的采样器,采样器中的采样瓶(包括瓶底衬盖、瓶底盖)与内拉杆、外套管通过螺纹联接,移动内拉杆、外套管,便可以方便地采取一定面积下的含油水柱。采样瓶装卸简单,运输方便,在实验室中可将其直接用作操作瓶。用这种采样器,计算结果将更接近真实情况。本装置已于92 年12 月30日获国家发明专利,专利号:89102471.9,证书号:16381。  相似文献   

11.
Passive samplers provide an excellent opportunity to perform indicative measurements or establish a dense network of measuring sites. A drawback compared with conventional active measuring methods is the larger spread of results. This variation can, to a large extent, be attributed to the influence of temperature, sampler geometry and wind on sampling results. A proper design of sampler geometry and optimum choice of draught shield can reduce the influence of wind velocity on a badge type sampler to less than 10%. Wire mesh screens prove to be inadequate in damping turbulence. Filters give good results. Attention should be paid to the size and isolation value of the walls of the sampler to prevent thermal updrafts occurring within the sampler. Tube type samplers are less influenced by wind, provided that turbulence is prevented from influencing diffusion within the sampler.  相似文献   

12.
Personal aerosol samplers are widely used to monitor human exposure to airborne materials. For bioaerosols, interest is growing in analyzing samples using molecular and immunological techniques. This paper presents a personal sampler that uses a two-stage cyclone to collect bioaerosols into disposable 1.5 ml Eppendorf-type microcentrifuge tubes. Samples can be processed in the tubes for polymerase chain reaction (PCR) or immunoassays, and the use of multiple stages fractionates aerosol particles by aerodynamic diameter. The sampler was tested using fluorescent microspheres and aerosolized fungal spores. The sampler had first and second stage cut-off diameters of 2.6 microm and 1.6 microm at 2 l min(-1)(geometric standard deviation, GSD = 1.45 and 1.75), and 1.8 microm and 1 microm at 3.5 l min(-1)(GSD = 1.42 and 1.55). The sampler aspiration efficiency was >or=98% at both flow rates for particles with aerodynamic diameters of 3.1 microm or less. For 6.2 microm particles, the aspiration efficiency was 89% at 2 l min(-1) and 96% at 3.5 l min(-1). At 3.5 l min(-1), the sampler collected 92% of aerosolized Aspergillus versicolor and Penicillium chrysogenum spores inside the two microcentrifuge tubes, with less than 0.4% of the spores collecting on the back-up filter. The design and techniques given here are suitable for personal bioaerosol sampling, and could also be adapted to design larger aerosol samplers for longer-term atmospheric and indoor air quality sampling.  相似文献   

13.
This study describes the field evaluation of a tailor-made new glass passive sampler developed for the determination of NO(2), based on the collection on triethanolemine (TEA)-coated fibre filter paper. The sampler has been derived from a Palmes design. The overall uncertainty of the sampler was determined by using Griess-Saltzman ASTM D 1607 standard test method as a reference method. The agreement between the results of the passive sampler and the reference method was +/-7.90% with the correlation coefficient of 0.90. Method precision in terms of coefficient of variance (CV) for three simultaneously applied passive samplers was 8.80%. The uptake rate of NO(2) was found to be 2.49 ml/min in a very good agreement with the value calculated from theory (2.63 ml/min). Sampler detection limit was 1.99 microg/m(3) for an exposure period of 1 week and the sampler can be stored safely for a period of up to 6 weeks before exposure. A comparison of the sampler performance was conducted against a commercially available diffusion tube (Gradko diffusion tube). The results from the applied statistical paired t test indicated that there was no significant difference between the performances of two passive samplers (R (2) > 0.90). Also, another statistical comparison was carried out between the dark and transparent glass passive samplers. The results from the dark-colour sampler were higher than that from the transparent sampler (approximately 25%) during the summer season because of the possible photodegradation of NO(2)-TEA complex.  相似文献   

14.
An understanding of the scaling laws governing aerosol sampler performance leads to new options for testing aerosol samplers at small scale in a small laboratory wind tunnel. Two methods are described in this paper. The first involves an extension of what is referred to as the "conventional" approach, in which scaled aerosol sampler systems are tested in a small wind tunnel while exposed to relatively monodisperse aerosols. Such aerosols are collected by test and reference samplers respectively and assessed gravimetrically. The new studies were carried out for a modified, low flowrate version of the IOM personal inhalable aerosol sampler. It was shown that such experiments can be carried out with a very high level of repeatability, and this supported the general validity of the aerosol sampler scaling laws. The second method involves a novel testing system and protocol for evaluating the performances of aerosol samplers. Here, scaled aerosol samplers of interest are exposed to polydisperse aerosols, again in a small wind tunnel. In this instance, the sampled particles are counted and sized using a direct-reading aerodynamic particle sizer (the APS). A prototype automated aerosol sampler testing system based on this approach was built and evaluated in preliminary experiments to determine the performance of another modified version of the IOM personal inhalable aerosol sampler. The design of the new test system accounts for the complex fluid mechanical coupling that occurs near the sampler inlet involving the transition between the external flow outside the sampler and the internal airflow inside the sampler, leading in turn to uncontrolled particle losses. The problem was overcome by the insertion of porous plastic foam plugs. where the penetration characteristics are well understood, into the entries of both the test and the reference samplers. Preliminary experiments with this new system also supported the general validity of the aerosol sampler scaling laws. In addition, they demonstrated high potential that this approach may be applied in a standardised aerosol testing method and protocol.  相似文献   

15.
The USEPA replaced TSP with PM10 as the National Ambient Air Quality Standard for particulate matter. The commercially available PM10 sampler is a high-volume model using quartz fiber filters. In certain investigations, such as source apportionment studies, chemical analysis of the filter is necessary, however, many analyses cannot be run on quartz filters. An alternate filter such as Teflon is amenable to XRF and ion chemical analyses but is not amenable to analysis for carbon. To overcome these problems DRI constructed a medium-volume PM10 sampler that is capable of collecting particulates on both Teflon and quartz fiber filters simultaneously. This paper describes the design of the DRI medium-volume PM10 sampler, discusses a method for determining equivalence of two samplers, the results of applying the method to test the equivalence of the medium-volume sampler and a commerical high-volume sampler, and examines differences between PM10 and TSP measurements in a southwestern desert.  相似文献   

16.
博物馆室内微环境中碱性气体的被动采样方法研究   总被引:1,自引:1,他引:0       下载免费PDF全文
针对博物馆微环境中的碱性污染气体-氨气,采用自行研制的被动采样器,建立了一套适合博物馆馆藏文物保存环境中氨气含量分析的被动采样-离子色谱检测方法,应用于博物馆的实地采样分析,通过与主动法采样对照,获得了被动采样器在博物馆微环境中氨的吸收系数,从而获得采样点空气中氨气的浓度,为博物馆文物保存环境监测提供了可行方法。  相似文献   

17.
The Respicon has been introduced as a sampler for health related measurements of airborne contaminants at workplaces. The instrument is aimed at simultaneous collection of three health related aerosol fractions: (a) the coarser inhalable fraction, defining the aerosol fraction that may enter the nose and mouth during breathing; (b) the intermediate thoracic fraction, defining the fraction that may penetrate beyond the larynx and so reach the lung; and (c) the finer respirable fraction, defining the fraction that may penetrate to gas exchange region of the lung. The instrument has a number of features attractive to occupational hygienists: in addition to providing the three aerosol fractions simultaneously, it is light and compact enough to be used as a personal sampler. yet can be a tripod mounted for area sampling, it can provide samples not only for gravimetric analysis but also microscopic and chemical analyses; and it is also available in a photometric direct-reading version. The instrument has previously been evaluated as an area sampler and, in this mode of operation, has shown reasonable accuracy in collecting respirable, thoracic and inhalable particles, the latter up to particle diameters of ca. 80 microm. Except for some scattered unpublished data there exist no systematic investigations in the Respicon's performance when used as a personal sampler in the industrial environment. In this paper, we will report on a study of side by side comparison of the Respicon with the IOM inhalable sampler, regarded as a reference instrument for the inhalable fraction. The main study was performed at six different workplaces in a nickel refinery. Statistical analysis of the gravimetrically-determined concentration data reveals consistently lower aerosol exposure values for the Respicon as compared to the IOM sampler. The data for the nickel workplaces are compared with findings from other studies. The results are interpreted in the light of the overall results and the possibility of introducing a correction factor is discussed.  相似文献   

18.
One of the major limitations in advancing the understanding of tropospheric ozone and aerosol generation and developing strategies for their control is the technical ability to accurately measure volatile organic compounds (VOCs). This paper describes the design of a constant flow VOC sampler. The versatile sampler can be used for fully automated concentration and flux measurements of VOCs. The sampler incorporates a microprocessor control unit and provides highly accurate mass flow control and significant ease of operation. Sampling sequences can be programmed directly or by remote control through a PC. All important operational parameters necessary for a complete sampling audit trail are logged. Compact weatherproof housings and low power consumption allow operation at remote sites and locations which are sensitive to disturbances or have restricted access. Inner wetted surfaces of the sampler are constructed from non-contaminating materials that do not sorb or emit VOC, and thus permit the collection of representative samples even in environments with very low VOC concentrations. The cartridge magazine provides a maximum of 20 sequential cartridge samples, which allows for long-term air quality assessments. In the dual channel mode, two samples can be collected simultaneously through two independent sample loops, providing ten sequential sample pairs. This design allows the parallel collection of (a) quality assurance backup samples, (b) samples on two different types of cartridges/sorbents to allow a variety of analyses, or (c) differential samples for flux measurements using enclosure, aerodynamic profile, or relaxed eddy accumulation (REA) methods. Field applications including airplane profile measurements above a tropical rainforest area, as well as gradient and REA measurements over a mid-latitude mixed forest stand are described, and demonstrate the validity and flexibility of the system. In particular, the application of the VOC sampler as an integrated part of a REA system is emphasized.  相似文献   

19.
Suddenly occurring and time limited chemical exposures caused by unintended incidents might pose a threat to many workers at various work sites. Monitoring of exposure during such occasional incidents is challenging. In this study a compact, low-weight and personal semi-automatic pumped unit for sampling of organic vapor phase compounds from occupational air during sporadic and suddenly occurring incidents has been developed, providing simple activation by the worker potentially subjected to the sudden occurring exposures when a trained occupational hygienist is not available. The sampler encompasses a tube (glass or stainless steel) containing an adsorbent material in combination with a small membrane pump, where the adsorbent is capped at both ends by gas tight solenoid valves. The sampler is operated by a conventional 9 V battery which tolerates long storage time (at least one year), and is activated by pulling a pin followed by automatic operation and subsequent closing of valves, prior to shipping to a laboratory. The adjustable sampling air flow rate and the sampling time are pre-programmed with a standard setting of 200 mL min(-1) and 30 min, respectively. The average airflow in the time interval 25-30 min compared to average airflow in the interval 2-7 min was 92-95% (n = 6), while the flow rate between-assay precisions (RSD) for six different samplers on three days each were in the range 0.5-3.7%. Incident sampler recoveries of VOCs from a generated VOC atmosphere relative to a validated standard method were between 95 and 102% (+/-4-5%). The valves that seal the sampler adsorbent during storage have been shown to prevent an external VOC atmosphere (500 mg m(-3)) to enter the adsorbent tube, in addition to that the sampler adsorbent is storable for at least one month due to absence of ingress of contaminants from internal parts. The sampler was also suitable for trapping of semi-volatile organophosphates.  相似文献   

20.
自动顶空-气相色谱法测定水中甲醇的方法优化   总被引:1,自引:0,他引:1  
从顶空进样器载气压力、顶空瓶压力、顶空瓶温度等方面对自动顶空-气相色谱法测定水中甲醇的方法进行了优化。该方法的灵敏度高于直接进样(水溶液)法、已有的顶空进样法,满足《空气和废气监测分析方法》(第4版)中吸收液中甲醇检出限0.4 mg/L的要求。  相似文献   

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