Hamon 10 × 100 MΩ resistor based traceable source for calibration of picoammeters in the range 100 pA–100 nA

This paper describes a measurement method developed at National Institute of metrological Research (INRIM) to calibrate picoammeters in dc current from 100 pA to 100 nA. The current source is based on a traceable to the dc resistance national standard 10 × 100 MΩ Hamon resistor developed at INRIM and on a traceable to the dc voltage national standard high precision dc voltage calibrator. The expanded uncertainties of the method for the calibration of picoammeters span from 9.4 × 10⁻⁴ for the gain of a picoammeter at 100 pA to 4.0 × 10⁻⁴ for the gain at 100 nA. A detailed uncertainties budget at 10 nA level and the results of a comparison with a different technique are also reported.     

Drilling of microholes down to 10 μm in diameter using ultrasonic grinding

Drilling by grinding is useful for fabricating holes in hard and brittle materials with high dimensional accuracy and low machining cost. However, its application to microholes has been limited to those with a diameter on the submillimeter order. The drilling of microholes less than 0.1 mm in diameter by grinding was therefore attempted on crown glass. Cemented tungsten carbide micropins were fabricated by electrical discharge machining and used as micro-grinding tools. They can be employed because the convex parts of discharge craters formed on the tool surfaces serve as cutting edges of abrasive grains of grinding wheels. In order to reduce grinding force and thus prevent tool breakage, ultrasonic grinding was employed with the workpieces ultrasonically oscillated. As a result, microholes down to 10 μm in diameter were successfully drilled. They are the smallest-diameter holes drilled by grinding, to the best of our knowledge. The effect of helical feeding, in which the tool not only rotates around its axis but also moves in planetary motion, on drilling properties was also investigated.     

Construction of a standard force machine for the range of 100 μN–200 mN

A new force standard machine (FSM) for the range of 100 μN–100 mN has been developed [1]. The machine is based on the comparison of a force transducer with the indication of an electromagnetic compensated balance (ECB). Construction details as well as first measurements will be presented. To guarantee traceability to the established deadweight force machines, the new facility was compared with the PTB 200 N FSM.     

Inter-laboratories comparison at 100 GΩ and 1 TΩ level to evaluate the traceability transfer from INRIM in the field of high dc resistance

A National inter-laboratories comparison of dc resistance at 100 GΩ and 1 TΩ among the National Institute of Metrological Research (INRIM) and eight Secondary Electrical Calibration Laboratories was carried out in 2010. All the involved Laboratories made their measurements with a method based on a Multifunction Calibrator (MFC) and on a digital multimeter (DMM), both used in their dc voltage function.These and other Secondary Electrical Laboratories are traceable to National Standards by means of the calibration at INRIM of a complete set of primary standards or, alternatively, by means of the calibration of a high accuracy DMM or of a Multifunction Transfer Standard (MTS) or of few primary standards. All the relative differences between each Laboratory’s value and its reference value obtained in the comparison were within their relative expanded uncertainties. This result showed that the traceability transfer methods from INRIM to Electrical Secondary Laboratories lead to satisfactory results in the field of high dc resistance.     

Analysis of composition dependence of some thermal transport properties in glassy Se80−xTe20Snx (0 ⩽ x ⩽ 10) alloys using transient plane source measurements

In the present work, we have studied simultaneous measurements of thermal transport properties (effective thermal conductivity, diffusivity, specific heat per unit volume, thermal inertia I_T) of glassy Se_80−xTe₂₀Sn_x (0 ? x ? 10) system using their twin pellets. The glassy system is prepared under a load of 5 tons and measurements have been made at room temperature using Transient Plane Source (TPS) technique. The composition dependence of the thermal transport properties of given glassy system is also discussed.     

Positive effect of natural pre-ageing on precipitation hardening in Al–0.44 at% Mg–0.38 at% Si alloy

Age hardening in a purely ternary Al-Mg0.4–Si0.4 (0.44 at% Mg, 0.38at%Si) alloy that is similar to AA6060 was investigated by hardness measurement, TEM and three-dimensional atom probe (3D-AP). In particular, the effect of natural pre-ageing before artificial ageing, which is known to have a positive effect in this alloy, was studied by comparing three different conditions: natural ageing only, artificial ageing for 1.5 h at 180 °C only and combined natural pre-ageing and subsequent artificial ageing for 1.5 h at 180 °C. Natural ageing influences the mechanical properties significantly. Naturally aged alloys exhibit a hardening response that is governed by the presence of small clusters. Subsequent artificial ageing of naturally aged specimens increases the value of peak hardness, which is attributed to the increase of the number density of needle-shaped precipitates as compared to the samples without natural ageing. It is assumed that besides these precipitates, the small Si clusters formed at room-temperature storage remain stable during artificial ageing.     

The influence of elastic strain on the early stages of decomposition in Cu–1.7 at% Fe

The initial stage of decomposition of homogenized Cu–1.7 at% Fe at 722 K was investigated by means of field ion microscopy (FIM), atom probe tomography (APT) and computer-assisted field ion image tomography (cFIIT). The agglomeration of atoms depending on time could be investigated and the growth of precipitates with a diameter of few nanometers was observed during ongoing nucleation.     

Computer simulation of a 1.0 GPa piston–cylinder assembly using finite element analysis (FEA)

The paper reports a preliminary study of the behavior of a high performance controlled-clearance piston gauge (CCPG) in the pressure range up to 1 GPa through finite elemental analysis (FEA). The details of the experimental characterization of this CCPG has already been published (Yadav et al., 2007 [1]). We have already pointed out that the use of Heydemann–Welch (HW) model for the characterization of any CCPG, has some limitation due to the fact that the linear extrapolation of the cube root of the fall rate versus jacket pressure (v^1/3–p_j) curve is assumed to be independent of the rheological properties of the pressure transmitting fluids. The FEA technique addresses this problem through simulation and optimization with a standard ANSYS program where the material properties of the piston and cylinder, pressure dependent density and viscosity of the pressure transmitting fluid etc. are to be used as the input parameters. Thus it provides characterization of a pressure balance in terms of effective area and distortion coefficient of the piston and cylinder. The present paper describes the results obtained on systematic studies carried out on the effect of gap profile between piston and cylinder of this controlled-clearance piston gauge, under the influence of applied pressure (p) from 100 MPa to 1000 MPa, on the pressure distortion coefficient (λ) of the assembly. The gap profile is also studied at different applied jacket pressure (p_j) such that p_j/p varied from 0.3, 0.4 and 0.5.     

1–15,000 Pa Absolute mode comparisons between the NIST ultrasonic interferometer manometers and non-rotating force-balanced piston gauges

The National Institute of Standards and Technology (NIST) Low Pressure Manometry Project maintains and operates primary standard ultrasonic interferometer manometers (UIMs) over the pressure range of 1 mPa to 360 kPa. Over the past decade a new type of customer gauge, the non-rotating force-balanced piston gauge or FPG (model 8601, DH Instruments, a Fluke Company¹) has been introduced to the standards community that covers the range of ≈1–15,000 Pa and is capable of both absolute and differential measurement modes. Since 2002, NIST customers² have requested that four different FPG units be compared to the NIST primary pressure ultrasonic interferometer manometer standards (UIMs). The results of the comparisons were that all four FPG units were within manufacturers stated uncertainty (0.008 Pa + 30 × 10⁻⁶ × P for absolute mode) when compared against the NIST UIMs at pressures between 10 Pa and 15,000 Pa (absolute mode). At pressures between 5 Pa and 10 Pa, the results were generally within manufacturer’s specifications. Below 5 Pa some of the FPG units were outside of manufacturer’s uncertainty specifications. The use of an isolating capacitance diaphragm gauge (CDG) was necessary during the comparisons to prevent humidified gas from the FPG from entering the NIST 160 kPa mercury UIM primary pressure standard. The results of these four different comparison tests will be discussed in detail, along with test conditions, equipment set-up, and test uncertainty analysis.     

Altair正式发布HyperWorks10．0

美国AltairEngineering公司近日正式发布AltairHyperWorks10．0。这个新版本升级了所有模块,对Radioss求解器解决方案进行了大幅的功能延伸和速度提升,首创多项创新的优化设计技术,引入了一个全新的数值分析软件技术,并且进一步巩固了HyperWorks在建模和可视化技术上的市场领先地位。     

Wonderware InTouch10．0／System Platform 3．0亮相

Wonderware In Touch10．0和SystemPlatform3．0新产品的发布活动于9月26日在上海举行。Wonderware亚太区总裁吴俊庆先生、美国资深专家和中国区总经理等一行人悉数亮相。亚太区总裁吴俊庆先生首先介绍了Wonderware品牌及发展现状。随后．美国资深专家和中国区总经理一起介绍了InTouch10．0和SystemPlatform3．0两款新品。[第一段]     

The use of carbon-cathode penning discharge cells to evacuate xenon over a pressure range of 10<Superscript>−3</Superscript>–10<Superscript>−4</Superscript> Torr

Experimental data are presented as proof that the Penning discharge in a carbon-cathode cell can be used to reduce (or regulate) the Xe pressure in the working chamber of an ultrahigh vacuum system from 2 × 10^–3 to 2 × 10^–4 Torr. Sorption of Xe is attributed to the implantation of accelerated ions in the porous structure of the surface carbon layers formed while the cathodes are being prepared from a powdered material and under ion bombardment. As the Xe pressure is lowered within the above limits, the evacuation rate decreases from 0.045 L/s to zero. The time dependence of the evacuation rate is governed by the initial Xe pressure.Translated from Pribory i Tekhnika Eksperimenta, No. 1, 2005, pp. 146–148.Original Russian Text Copyright © 2004 by Kozlovskii, Tamanis.     

云计算助力制造业管理走向2&#183;0时代

业界曾有人将云计算的影响力比喻成为是从古老的单台发电机向发电厂集中供电模式的一大转变。它意味着计算能力可以作为一种商品进行自由流通与交易，就像煤气和水电一样，取用方便，价格低廉。     

0—10mm精密自锁钻卡头

我厂的老师傅在使用一般的钻卡头时,深感要用专用钥匙扳紧扳松的不便。一是扳动时钥匙常打滑;二是钥匙易遗失;三是当切削力大于扳紧力时,钻头打滑,柄部咬毛。遵照伟大领袖毛主席要“大搞技术革新”的教导,以批修整风为纲,我们设计制造了一种自锁式钻卡头,把专用钥匙的“命”革掉了。使用这种卡头,只要用手轻轻地转动一     

小松 PC215-10M0型履带式挖掘机

正产品亮点配置最新研发的发动机控制系统,搭载小松特有的闭式负荷感应系统,燃油经济性能提高10%,发动机功率提升12%,作业效率提高20%。2019年销售397台,同吨位市场占有率14.8%。小松PC215-10M0型履带式挖掘机工作质量21.5t,配装小松SAA6D107E-1型发动机,发动机额定功率123k W,铲斗容量1.0～1.06m~3。通过升级发动机和主泵的     

阿特拉斯&#183;科普柯的PET吹瓶压缩机首次通过Class0认证

2008年9月15日,阿特拉斯&#183;科普柯宣布该公司旗下的ZD高压压缩机成为世界上首台可为PET包装生产提供安全性通过100％无油空气认证和Class0认证的压缩机。该款压缩机具有下列特点：1提供100％无油空气。油污染是所有装瓶设备和无菌环境中的隐形敌人。阿特拉斯&#183;科普柯的40barZD压缩机凭借其独特的设计,完全消除了因油污染而引发的风险。     

Z－0．4／10型空气压缩机的改进

介绍了Ｚ－０．４／１０型空气压缩机的结构改进，分析了结构改进对功耗的影响，给出了改进前后的性能参数对比。     

A shaper of multiply repeated picosecond high-voltage pulses in a range of 10<Superscript>−10</Superscript> s

A pulse-shaping device is described that reproduces multiply repeated picosecond high-voltage pulses with a duration of 10^?10 s, an amplitude of >100 kV, and a repetition rate of up to 10³ Hz. The principle of switching the circuit using a single spark gap filled with a compressed gas instead of conventional spark peakers and a chopping gap, connected in series, is applied. The use of compressed hydrogen at a pressure of 30 atm as the working gas favors stability of the discharge voltage and a virtually unlimited lifetime of the shaping device.     

A photo-thermally stimulated exoemission technique used to study the properties of HTSC ceramics based on YBa<Subscript>2</Subscript>Cu<Subscript>3</Subscript>O<Subscript>7−δ</Subscript>

The method of photo-thermally stimulated exoelectron emission (PTSE) is used to study the processes in the surface layers of HTSC ceramics based on YBa₂Cu₃O_7–. A correlation is observed between variations of the exoemission current and the transition to the superconducting state. The experimentally detected hysteresis in the PTSE intensity of YBa₂Cu₃O_7– ceramics, when thermally cycled in the range T=80–160 K, is limited by two processes. Below T=90 K, the chemisorption has a significant effect on the physical phenomena under study, thus impeding the search for new PTSE regularities in HTSC ceramics. At the same time, exoemission properties of the ceramics considerably change in the range 80–160 K. It is also shown that the superconducting transition and the thermal absorption phenomena for an YBa₂Cu₃O_6.8 specimen are split in the studied temperature range, which allows the PTSE technique to detect the superconducting state and to observe the transition dynamics.Translated from Defektoskopiya, Vol. 40, No. 12, 2004, pp. 54–59.Original Russian Text Copyright © 2004 by Syurdo, Kortov, Milman, Slesarev, Mikhailovich.This revised version was published online in April 2005 with a corrected cover date.