In-flight Energy Calibration of the GECAM Gamma-ray Detectors

The Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor(GECAM)mission is designed to monitor the Gamma-Ray Bursts(GRBs)associated with gravitational waves and other high-energy transient sources.The mission consists of two microsatellites which are planned to operate at the opposite sides of the Earth.Each GECAM satellite could detect and localize GRBs in about 8 keV-5 MeV with its 25 Gamma-Ray Detectors(GRDs).In this work,we report the in-flight energy calibration of GRDs using the characteristic gamma-ray lines in the background spectra,and show their performance evolution during the commissioning phase.Besides,a preliminary cross-calibration of energy response with Fermi GBM data is also presented,validating the energy response of GRDs.

Performances of different efficiency calibration methods of high-purity-germanium gamma-ray spectrometry in an inter-comparison exercise

This study reports the performances of efficiency calibrations for high-purity-germanium gamma-ray spectrometry using the source-, Laboratory Sourceless Object Calibration Software(LabSOCS)-and ANGLE-based methods in an inter-comparison exercise. Although the results of LabSOCS and ANGLE for ^(241)Am emitting lowenergy gamma rays were not very satisfactory, all of the three efficiency calibration methods passed acceptance criteria. The results confirmed the reliability of the calculation codes ANGLE and LabSOCS as alternative efficiency calibration methods in high-purity-germanium gamma spectrometry. This study is likely to promote the further application of the ANGLE and LabSOCS calculation codes in radioactivity measurements.

A new calibration method for radon detector in seismic systems

Radon observation is an important measurement item of seismic precursor network observation.The radon detector calibration is a key technical link for ensuring radon observation accuracy.At present,the radon detector calibration in seismic systems in China is faced with a series of bottleneck problems,such as aging and scrap,acquisition difficulties,high supervision costs,and transportation limitations of radon sources.As a result,a large number of radon detectors cannot be accurately calibrated regularly,seriously affecting the accuracy and reliability of radon observation data in China.To solve this problem,a new calibration method for radon detectors was established.The advantage of this method is that the dangerous radioactive substance,i.e.,the radon source,can be avoided,but only“standard instruments”and water samples with certain dissolved radon concentrations can be used to realize radon detector calibration.This method avoids the risk of radioactive leakage and solves the current widespread difficulties and bottleneck of radon detector calibration in seismic systems in China.The comparison experiment with the traditional calibration method shows that the error of the calibration coefficient obtained by the new method is less than 5%compared with that by the traditional method,which meets the requirements of seismic observation systems,confirming the reliability of the new method.This new method can completely replace the traditional calibration method of using a radon source in seismic systems.

Study on calibration period of Gas Sensor in exercise Pulmonary Function instrument

Objective: to study the calibration period of the main motor pulmonary function instru-ment sensor. Methods: A matched control group was used, one was calibrated periodical-ly and the other was not calibrated. The calibration values of oxygen sensor and carbon dioxide sensor were compared. Results: the oxygen sensor of electrochemical type was most sensitive to the change of time and environment, and the carbon dioxide sensor of infrared type was more sensitive to the change of time and environment. Conclusion: ox-ygen sensors of electrochemical type and carbon dioxide sensors of infrared type should be calibrated before each use.

National Verification Regulations and Calibration Specifications of Measuring Instruments of P.R.China in 2010(2010 No.131)

General Administration of Quality Supervision,Inspection and Quarantine of P.R.China has approved the following 8 national measuring verification regulations in 2010 and publicize now.

National Verification Regulations and Calibration Specifications of Measuring Instruments of P.R.China in 2008 2008 NO.35

General Administration of Quality Supervision,Inspection and Quarantine of P.R.China has approved the following 11 national measuring verification regulations in 2008 and publicize now.

National Verification Regulations and Calibration Specifications of Measuring Instruments of P.R.China in 2008

General Administration of Quality Supervision,Inspection and Quarantine of P.R.China hasapproved the following 24 national measuring verification regulations in 2008 and publicize now.

National Verification Regulations and Calibration Specifications of Measuring Instruments of P.R.China in 2008 2008 No.22

General Administration of Quality Supervision,Inspection and Quarantine of P.R.China has approved the following 10 national measuring verification regulations in 2008 and publicize now.

Method for array gain and phase uncertainties calibration based on ISM and ESPRIT

A new method for array calibration of array gain and phase uncertainties, which severely degrade the performance of spatial spectrum estimation, is presented. The method is based on the idea of the instrumental sensors method （ISM）, two well-calibrated sensors are added into the original array. By applying the principle of estimation of signal parameters via rotational invariance techniques （ESPRIT）, the direction-of-arrivals （DOAs） and uncertainties can be estimated simultaneously through eigen-decomposition. Compared with the conventional ones, this new method has less computational complexity while has higher estimation precision, what＇s more, it can overcome the problem of ambiguity. Both theoretical analysis and computer simulations show the effectiveness of the proposed method.

Sensor Calibration in Support for NOAA's Satellite Mission

Sensor calibration, including its definition, purpose, traceability options, methodology, complexity, and importance, is examined in this paper in the context of supporting NOAA＇s satellite mission. Common understanding of sensor calibration is essential for the effective communication among sensor vendors, calibration scientists, satellite operators, program managers, and remote sensing data users, who must cooperate to ensure that a nation＇s strategic investment in a sophisticated operational environmental satellite system serves the nation＇s interest and enhances the human lives around the world. Examples of calibration activities at NOAA/NESDIS/ORA are selected to further illustrate these concepts and to demonstrate the lessons learned from the past experience.

Calibration of the DAMPE Plastic Scintillator Detector and its on-orbit performance

The DArk Matter Particle Explorer(DAMPE) is a space-borne apparatus for detecting the highenergy cosmic-ray-like electrons, γ-rays, protons and heavy ions. The Plastic Scintillator Detector(PSD)is the top-most sub-detector of the DAMPE. The PSD is designed to measure the charge of incident highenergy particles and it also serves as a veto detector for discriminating γ-rays from charged particles. In this paper, a PSD on-orbit calibration procedure is described, which includes the five steps of pedestal, dynode correlation, response to minimum-ionizing particles, light attenuation function and energy reconstruction.A method for reconstructing the charge of incident high energy cosmic-ray particles is introduced. The detection efficiency of each PSD strip is verified to be above 99.5%; the total efficiency of the PSD for charged particles is above 99.99%.

Dynamic Calibrating Technique for Super－Precision Gyrorotor Measuring Instrument

To ensure the accuracy of measurement in dynamic calibrating systems an important problem in the process of super-precision measuring gyrorotor.The conventional calibrating method which seriously affects the precision of measurement is analyzed systematically,and a statistical dynamic calibrating method is suggested in this paper.Test results indicate that the suggested method can significantly improve the calibrating process and system accuracy which is less than 0.05%.

Towards Quantitative Characterisation of the Small Force Transducer Used in Nanoindentation Instruments

Quantitative characterization of the mechanical properties of materials in micro-/nano-scale using depth-sensing indentation technique demands high performance of nanoindentation instruments in use. In this paper, the efforts to calibrate the capacitive force transducer of a commercial nanoindentation instrument are presented, where the quasi-static characteristic of the force transducer has been calibrated by a precise compensation balance with a resolution of ~1 nN. To investigate the dynamic response of the transducer, an electrostatic MEMS (Micro-Electro-Mechanical System) based on nano-force transfer standard with nano-Newton (10-9 Newton) resolution and a bandwidth up to 6 kHz have been employed. Preliminary experimental results indicate that 1) the force transducer under calibration has a probing force uncertainty less than 300 nN (1σ) in the calibration range of 1 mN;2) the transient duration at contact points amounts to 10 seconds;3) the overshoot of engagement is pre-load dependent.

Low-Cost 4-20 mA Loop Calibrator

Instrument calibration is vital to a successful control system because signal inputs to the system controllers come from such instruments. This paper presents a method for actualizing a standard low-cost loop calibrator for the famous 4-20 mA electrical signaling scheme. The loop calibrator generates a linear current signal from 4 to 20 mA over a 250 ? typical process instrument load for calibration. The realization of the loop calibrator relies on a voltage-to-current converter to build a constant current source. The voltage controlled constant current source is built from discrete components and an op-amp to keep the cost low. Results from simulations and the prototype demonstrate the performance of the 4-20 mA loop calibrator which utilizes a greatly reduced number of components. The cost of these components is approximately 34% of the least expensive calibrator sampled, though other production costs are not included. This conclusion reinforces the fact that loop calibrators can be cheaper.

泰安台水管仪标定故障典型实例

针对泰安台DSQ水管仪在2020年的年中、年终标定中出现NS向多次重复标定均不合格的情况,通过分析标定过程中单端电压差值的变化,判断为标定装置中的水银掉落导致N端堵塞,经检修后标定合格。此次典型故障排查中分析电压差变化规律的方法,对台站水管仪的运行维护、标定故障识别有很好的借鉴和指导意义。

一种基于虚拟仪器技术的视频分析仪校准装置

针对视频分析仪校准中主要标准器停产以及校准过程繁琐的问题,基于虚拟仪器技术,在LabVIEW开发环境下,利用M4i.6622-x8任意波形发生卡作为信号发生模块,开发了一种视频分析仪校准装置。实现了视频分析仪基本参数和失真参数的校准,给出了亮度电平、色度电平、色度相位等视频基本参数和行倾斜、k_(p)系数(2T脉冲k系数)、色度-亮度增益差、色度-亮度时延差、亮度非线性失真等视频失真参数的校准信号产生过程。经过实验,技术指标可达到如下:亮度电平为±0.2%,色度电平为±0.2%,色度相位为±0.1°,行倾斜为±0.1%,k_(p)系数为±0.1%,色度-亮度增益差为±0.2%,色度-亮度时延差为±3 ns,亮度非线性失真为±0.2%;优于TG2000可编程视频信号发生器,满足视频分析仪校准要求。

电梯制动器中的控制检验技术分析

阐述电梯制动器电气控制的原理、功能、重要性,分析常见问题,并介绍检验方法,包括检验目标、标准、流程和常见问题的识别与解决方案。提出提升电梯制动器电气控制可靠性和安全性的方法。

月球直射辐照度仪同光轴装调及传递定标

采用激光水平仪与平面反射镜相结合的方式,在实验室模拟月球对追踪相机与探测镜头进行同光轴装调,避免未同光轴导致测试不到信号或者信号太小造成数据不准确的问题,实验结果显示实验室同光轴装调误差在±0.03°以内。为保证仪器定标系数的准确性,采用已溯源于国家计量基准的标准灯传递定标微光灯的方式,利用激光测距仪与激光水平仪、平面反射镜相结合的方式保证传递定标精度,解决了直接使用标准灯定标带来的探测器非线性响应误差和长定标距离误差的难题。为地基对月观测仪器建立高精度的月球辐射模型提供了一种思路与解决方法。

刻蚀方式对金标准物质逸出功测量的影响

为了避免设备未合适校准带来的测量误差,在紫外光电子能谱(UPS)测试前进行标准物质逸出功(WF)的校准,对获得准确可靠的WF参考值至关重要.高纯金片(Au)性能稳定且具有清晰的费米边,是用于WF以及费米能级校准较为便利的标准参考物质.但是由于表面吸附及污染的存在,需要对Au标准物质进行离子刻蚀处理.采用不同的刻蚀方式对WF测量的影响进行研究,结果表明,栅格扫描刻蚀和定点刻蚀的方式不仅影响UPS测试谱图的质量,且随着刻蚀结束后停留时间的增加,分析室内的残余杂质分子会逐步吸附在Au表面,引起其WF的降低.同时由于定点刻蚀后表面不均匀性较大,有效刻蚀区域WF的平均值与标准值的相对误差达到10.48%.为保证UPS测量结果的准确性,建议在刻蚀完成后尽快进行WF测量.虽然栅格扫描刻蚀所使用时间较长,但是对样品的清洁效果以及测试的质量总体要优于定点刻蚀.