Circular displacement sensor using magnetostrictive amorphous wires

A sensor employs the properties of newly developed amorphous magnetic materials in wire form to measure angle and force. This paper describes the sensor construction in detail and discusses its behavior under the influence of several external factors. The overall performance of the sensor is also assessed     

铁基非晶合金磁致伸缩系数的研究

利用单辊熔体急冷法制备出Fe52Co34Zr7B6Cu1非晶合金薄带。利用中频脉冲磁场对淬态非晶合金进行磁脉冲处理,并利用自制的磁致伸缩系数测量系统和穆斯堡尔谱对脉冲磁场处理前后的非晶样品进行测量。结果表明,脉冲磁场处理后的样品发生了纳米晶化现象,晶化相主要为α-FeCo。随着脉冲磁场的增大,磁致伸缩系数出现了先减后增的变化,说明处理后的双相合金的磁学性能对于脉冲磁场的处理具有选择性。穆斯堡尔谱仪测试表明,试样经过脉冲磁场处理后整体上仍表现出明显的非晶态特征,随着脉冲磁场的增强,晶化量的百分比分别为9.9%,17.2%和28.3%。     

New extensometers using amorphous magnetostrictive ribbon wound cores

New reliable and accurate extensometers are presented using a single amorphous core multivibrator with a dc output. These extensometers can detect strains as large as 40 percent for tensile test samples without any destruction due to the outstanding elasticity of the Metglas 2605A amorphous ribbon-wound cores. High linearity (0.18 percent full scale (FS)) is realized by annealing and applying 1000 times alternating stresses to the cote. Hysteresis against alternating strains is removed to less than 0.48 percent FS by the effect of a compensation spring. The amorphous core extensometer has advantageous points regarding reliability, temperature stability, and maximum operating temperature over conventional extensometers using semiconductor strain gauges.     

An inspection policy for a deteriorating single-unit system characterized by a delay-time model

This paper develops a method for determining the discrete time points of inspection for a deteriorating system which is under condition-based maintenance. The system is regarded as a single component unit, and it has the following states: a normal state, a symptom state and a failed state. A delay-time model is utilized in order to describe the transition of the states. The transition time from a normal state to a symptom state and the transition time from a symptom state to a failed state are assumed to obey independent and identically distributed probability density functions respectively. Two types of probabilities with respect to inspections are considered: failed-dangerous (FD) probability or type I error that a system is wrongly diagnosed as in a normal state when the system is actually in a symptom state and failed-safe (FS) probability or type II error that a system is wrongly diagnosed as in a symptom state when the system is actually in a normal state. The determination method is formulated to minimize the long-run average cost per unit time with a constraint on inspection time. The nature and sensitivity of the proposed method is investigated under varying FD and FS probabilities and coefficients of variation.     

A delay-time model with safety constraint

We consider the basic delay-time model in which a system has three states, the perfect functioning state, a defective state and the failure state. The system is deteriorating and to reduce the number of failures, preventive replacements are carried out when the system is in the defective state. The time in the defective state is referred to as the delay time. Inspections are required to check whether the system is in the defective state. System failures are safety critical and to control the risk, management considers two types of safety constraints: (i) the probability of at least one failure in the interval [0,A] should not exceed a fixed probability ω₁ and (ii) the fraction of time the system is in the defective state should not exceed a fixed limit ω₂. The problem is to determine optimal inspection intervals T, minimizing the expected discounted costs under the safety constraints. Conditions are established for when the safety constraints affect the optimal inspection time and causes increased costs.     

A FASTBUS digitizer system for TOPAZ TPC

A large scale digitzer system for 11000 channels of the TOPAZ TPC was constructed based on FASTBUS and installed for TRISTAN at KEK. Each digitizer card is equipped with 16 channels of CCD with a moderate speed of A/D converter. Output data are arithmetically corrected for pedestals, zero-suppressed and applied with a PRE/POST mechanism by an on-board sequencer; they are followed by a sparse data scan with an intelligent data scanner.     

A transformer-type displacement digitizer with error compensation

A new precision circuit has been developed for a phase-type transformer displacement converter in which the errors of the phase shifter are balanced out; the working principle is described. __________ Translated from Izmeritel’naya Tekhnika, No. 10, pp. 26–27, October, 2007.     

Multi-hit drift time digitizer with one-nanosecond resolution

A multi-hit drift time digitizer is described (in the 16 μs range). It measures the time position of signals with an accuracy of 1 ns from a wide-gap drift chamber. A fast MECL memory (256 × 7 bits) in each information channel allows one to register up to 256 signals with a ? 64 ns interval between pulses.     

Magnetic and magnetostrictive properties of cube textured nickel for magnetostrictive transducer applications

Magnetic and magnetostrictive properties of {100} <100> textured, polycrystalline nickel sheet have been measured in the <100> direction and compared with a randomly oriented nickel sheet. The {100} <100> textured nickel produced a 51 percent increase in the available magnetostrictive strain energy along with a 21 percent decrease in sound velocity. These improved characteristics when combined with an equivalent electromechanical coupling coefficient and a nearly linear response of magnetostrictive strain to the applied magnetic field, make "cube" textured nickel sheet an attractive new material for many transducer applications.     

Methodology of using delay-time analysis for a manufacturing industry

This paper has been written to give a methodology of applying delay-time analysis to a maintenance and inspection department. The aim is to reduce downtime of plant items and/or reducing maintenance and inspection costs, taking into account the possible environmental impact of a failure in terms of cost, both to the company and the environment. The paper also attempts to give a subjective measure of the consequences of such a failure in terms of cost to the environment, in monetary value to the company and the damaging effect to the company image.     

磁弹性型磁致伸缩多层膜的研究与开发

本文介绍了近年来对磁弹性型磁致伸缩多层膜的研究与开发，论述了研究过程中所探索出的一些多层膜的制备理论；探讨了包括多层膜的靶材选择、单层膜厚、层数、组织结构和真空热处理对其性能的影响。     

A fast 2-bit digitizer for radio astronomy

The design and performance details for a 2-bit digitizer operating at a 250-MHz clock rate are presented. The digitizer is part of a new correlator system for a three-element millimeter-wave interferometer. The performance of the digitizer circuit is analyzed in terms of threshold errors, indecision, sampling aperture width, and timing errors. For an input bandwidth of 125 MHz, digitizer distortion actually improves the sensitivity of the interferometer by about 0.3% but limits the dynamic range of the instrument to about 2×10³