NCSL International Workshop & Symposium Conference Proceedings 2014最新文献

{"title":"Mitigating Electrostatic Effects on Measurement Accuracy","authors":"Greg Gumkowski, A. Steinman","doi":"10.51843/wsproceedings.2014.39","DOIUrl":"https://doi.org/10.51843/wsproceedings.2014.39","url":null,"abstract":"Electrostatic charge can have unwanted effects on the accuracy of instruments making precision weighing measurements. This paper will discuss electrostatic phenomena and their interaction with weighing operations. Charge is generated primarily by the contact and separation of dissimilar materials. If one of the materials is a conductor, charge can be quickly removed or even prevented by connecting the material to ground. In most cases, however, at least one of the materials will be an insulator or an isolated conductor. As contact and separation occurs throughout the weighing process, the materials involved are almost certain to be charged. A charged insulator is also capable of inducing charge on nearby isolated conductors. Examples of materials that may be charged include samples, transport media, and parts of weighing equipment or their enclosures. Once generated, the static charge affects both the instruments and the materials being weighed. Electrostatic forces interact directly with the mechanisms of weighing machines, making precise measurements in the microgram range all but impossible. Electrostatic forces of attraction and repulsion affect light weight sample materials, causing unwanted movement and losses during transfers, as well as the movement and clinging of unwanted particles to measurement surfaces. Measurement problems caused by static charge are not limited to weighing applications. Whenever small physical quantities or objects need to be measured, electrostatic forces can cause errors or unwanted movement of the object being measured. This is true for atomic force microscopes, force and mass measurements, and electrochemical measurements. Mitigation methods for static charge are well known in the electronics industry, as it is imperative to protect sensitive integrated circuits from the effects of static charge, both during manufacture and use. Grounding of conductive materials, replacing insulators with dissipative materials, and air ionization are the primary static control methods. Air ionization is of particular importance in weighing operations as equipment parts, samples or transport media are often insulators or isolated conductors. This paper discusses how static control may be applied in precision weighing operations, both in the equipment and in sample transport, to remove static charge and improve the accuracy and repeatability of measurements.","PeriodicalId":446344,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2014","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115127108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"How to Select the Appropriate Type of Control Chart in Metrology","authors":"C. Hung","doi":"10.51843/wsproceedings.2014.60","DOIUrl":"https://doi.org/10.51843/wsproceedings.2014.60","url":null,"abstract":"According to section 5.9 of ISO/IEC 17025:2005 [1], laboratories shall have quality control procedures for monitoring the validity of tests and calibrations undertaken. The resulting data shall be recorded in such a way that trends are detectable and, where practicable, statistical techniques shall be applied to the reviewing of the results. In order to meet the requirements given above, control charts are commonly used to monitor the stability of the measurement systems. However, based on the practical experiences in laboratories, inappropriate selection of process parameters or control charts may result in failure to detect the changes of measurement systems. For this reason, this paper focuses on how to select the appropriate types of control charts in metrology, such as for process parameters characterized by trend or lower resolution. In addition, some patterns are also provided to help the laboratory staffs detect the signals of measurement systems immediately. The accuracy of the measurement results could be ensured continuously through the correct use of the control charts.","PeriodicalId":446344,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2014","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115429009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of Proficiency Testing Results with a Drifting Artifact - An Example of Standard Resistor","authors":"C. Hung, Pin-Hao Wang, G. Peng","doi":"10.51843/wsproceedings.2014.01","DOIUrl":"https://doi.org/10.51843/wsproceedings.2014.01","url":null,"abstract":"Proficiency testing (PT) is evaluation of participant’s performance against pre-established criteria by means of interlaboratory comparisons. In the calibration field, the normalized error (En) is the most widely used performance statistic for determining the measurement capability of a calibration laboratory. One of the variables in the En equation is Uref, which is the expanded uncertainty of the reference laboratory’s assigned value. To evaluate a participant's performance effectively, if any effects of the PT scheme are significant, the additional uncertainties should be combined with the reference laboratory’s reported expanded uncertainty to estimate Uref. Among such uncertainties, the stability of artifacts is an important uncertainty component in the PT scheme, especially for a calibration laboratory. Based on practical PT experience, most artifacts can be regarded as sufficiently stable if the difference between three reference laboratory measurements is small. In such cases, the median of the three measurements is usually chosen as the assigned value, and its reported expanded uncertainty is used as the Uref value. However, some artifacts, such as standard resistors, drift over time. There is some uncertainty about how to accurately determine the assigned values and expanded uncertainties of these artifacts. The confidentiality of the participants' information must also be considered. This paper utilizes the PT scheme for standard resistors performed by CMS/ITRI to demonstrate the evaluation of PT results with a drifting artifact. The standard resistor measurement capability of each calibration laboratory in Taiwan is also provided.","PeriodicalId":446344,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2014","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114953281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Uncertainty Propogation for Measurements with Multiple Output Quantities","authors":"Michael Dobbert, B. Schrijver","doi":"10.51843/wsproceedings.2014.11","DOIUrl":"https://doi.org/10.51843/wsproceedings.2014.11","url":null,"abstract":"The ISO Guide to the Expression of Uncertainty in Measurement [1] (GUM) limits the description of the law of propagation of uncertainty to real input quantities and a single real output quantity. The GUM provides little guidance for uncertainty analysis of measurements with multiple output quantities, such as complex valued S-Parameter measurements that have both real and imaginary components. Complex measurement quantities are common in RF and microwave measurements. Likewise, measurements with multiple output quantities exist in many disciplines. Supplement 2 [2] to the GUM extends the law of propagation of uncertainty to an arbitrary number of output quantities, which is a more general solution. This paper discusses this more general solution clearly and concisely using matrix notation. It demonstrates that the GUM expressions for uncertainty propagation are a specific case of this more general solution. This method is then applied to a practical measurement uncertainty example involving complex quantities.","PeriodicalId":446344,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2014","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130679846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Self-Calibrated Method to Measure the Load Effect of the Resistor","authors":"Zhengkun Li, Jian Wu, Zhonghua Zhang, Q. He","doi":"10.51843/wsproceedings.2014.43","DOIUrl":"https://doi.org/10.51843/wsproceedings.2014.43","url":null,"abstract":"Since 1999, quantum Hall resistance (QHR) has been widely used as the primary standard of resistance in national metrology institutes (NMIs). The standard resistors can trace to the QHR standard by Cryogenic Current Comparator (CCC) bridge or Direct Current Comparator (DCC) bridge. In the calibration, the current applied to resistor should be a certain value. However, in most industrial applications, the current applied to the resistor is not the same as the one used in the calibrated procedure. Due to the temperature change from the resistor’s self-heating with current, the value of the resistor will also change, which is called load effect. Besides, the load effect is also determined by the environment temperature. Thus in many precise measurements, the load effect or power coefficient of the resistor should be considered and evaluated. So far, there is not an instrument can be used to measure the load effect of a resistor directly. Lack of a standard resistor with known load effect is also a problem. Here, a self-calibrated method is proposed to get the load coefficient of a resistor at different temperature. A series of 500 ohm resistor components with the same temperature coefficient is used to form a 100 ohm resistor and a 20 ohm resistor by series-parallel connection. A DCC bridge is used to compare two resistors at 1 volt and 0.5 volt alternately. The power change of 500 ohm component in 20 ohm resistor is 4 times of that in 100 ohm resistor. Thus the ratio change is mainly from the change of the 20 ohm resistor and the load coefficient can be got with this approach. The 100 ohm resistor is put in an oil bath with fixed temperature, and the 20 ohm resistor is put in another oil bath, which temperature is changed to get the load coefficient of the 20 ohm resistor at different temperature. Measurement results show that the load coefficient of the 20 ohm resistor is at 1E-9 level when the oil bath is set at 23.5 degree. Then it can be used as a reference to measure the load coefficient of other resistors.","PeriodicalId":446344,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2014","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123997265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Laboratory Analysis of Force  Required to Fill a Syringe","authors":"J. Fuehne","doi":"10.51843/wsproceedings.2014.59","DOIUrl":"https://doi.org/10.51843/wsproceedings.2014.59","url":null,"abstract":"Nurses routinely withdraw fluid from the stomachs of intensive care patients who are being provided nutrition intravenously in order to determine if the patient is properly tolerating the liquid nutrition. This is a critical measurement in patient care. If too little liquid nutrition is being provided, the patient will not follow a path of optimal healing. If too much liquid is being provided, the patient may have issues with the esophagus or have fluid get into the lungs, leading to pneumonia. The purpose of this work is to conduct a laboratory study to investigate the process of drawing fluid through a syringe in an environmentally-controlled laboratory. A force measurement system is used that includes the ability to control the displacement and speed of the syringe pump. Additionally, laboratory data from the force measurement system are presented for different tube materials, different tube diameters, and different fluids with varying viscosity. Viscosity is also determined by using a falling-ball viscosimeter test in the lab. The force required to withdraw fluid for each of these variables is studied. The amount of fluid withdrawn for each combination of variables is recorded in light of attempting to provide guidance to nurses and other health care providers about the best way to obtain the required data and keep patients healthy.","PeriodicalId":446344,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2014","volume":"319 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125825715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Using SAP Business Management Software to  Manage Test & Measuring Equipment","authors":"G. Mihm","doi":"10.51843/wsproceedings.2014.53","DOIUrl":"https://doi.org/10.51843/wsproceedings.2014.53","url":null,"abstract":"SAP is a well-known name in the business management software market. The German Armed Forces Calibration Service uses SAP for more than two years now. Announced as “a perfect business solution”, SAP first turned out to be a nightmare and finally became a useable tool •with advantages and disadvantages, too. The presentation will give an overview over the experiences made. It will include the idea behind the system, show en detail how every single piece of test- and measurement equipment • known as “equipment” or “equi” - has to be set up in the system, explains how service plans and on-time notifications have to be handled, how templates have to be created and how customers and calibration technicians have to work with this software. The presentation will not try to sell SAP • but give an idea how the equipment management of test- & measurement equipment can be handled and might help to make decisions.","PeriodicalId":446344,"journal":{"name":"NCSL International Workshop & Symposium Conference Proceedings 2014","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125772612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}