法医实验室精密电子天平（电磁力平衡式）刑事技术实验室与司法鉴定合规应用介绍

作者：毕思特科技来源：毕思特科技浏览数：15 发布时间：2026/4/13 8:38:30

法医实验室精密电子天平（电磁力平衡式）刑事技术实验室与司法鉴定合规应用介绍

【重要合规前置声明】本设备为法医实验室、刑事技术检验专用法定计量器具，仅面向具备法定法医物证鉴定、毒物毒品分析、微量物证检验资质的公安、检察、司法行政、司法鉴定等国家机关及授权鉴定机构定向研发、生产与销售，不向任何个人、无资质企业及非授权单位提供。本设备的安装、使用、校准与维护，必须严格遵守《中华人民共和国计量法》《中华人民共和国刑事诉讼法》《中华人民共和国司法鉴定程序通则》《法庭科学 DNA 实验室规范》《实验室资质认定评审准则》及 JJG 1036-2022《电子天平》国家计量检定规程，必须由经过专业培训的实验室技术人员规范操作，按期完成法定计量检定与性能验证，严禁无资质人员违规使用，严禁因计量失准、操作不当导致涉案检材损毁、检验数据失真、司法鉴定证据失效。

产品概述

法医实验室精密电子天平（电磁力平衡式），是一款基于高精度电磁力平衡传感器打造的专业称量计量仪器，专为刑事科学技术实验室涉案物证、检材及实验试剂的精确质量计量需求深度定制。本设备的核心价值，在于为法医毒物定量分析、DNA 检验试剂配制、微量物证理化检验、标准溶液制备等关键司法鉴定环节，提供毫克级的高精度、高稳定性质量计量数据。设备集成了智能校准、全功能称量模式、完备的故障自诊断系统与可追溯数据管理功能，可确保从涉案样本制备到检验数据分析全流程中，计量数据的准确性、可追溯性与可靠性，是维护司法鉴定科学性、公正性与证据法律效力的核心基础计量保障设备。

技术原理

本天平采用专利一体连杆式电磁力平衡传感器技术，核心基于电磁力与重力平衡的物理原理实现高精度质量计量，彻底规避了传统机械天平的摩擦损耗与精度衰减问题，具备高灵敏度、快速响应、优异长期稳定性的核心优势，完美适配法医实验室微量、珍贵涉案检材的称量需求。当被测物放置于秤盘上时，其重力会带动传感器的杠杆系统发生精准位移，该位移量会被高精度位置检测器实时捕获并转换为电信号，同步反馈至闭环控制电路。控制电路随即生成与重力大小精准匹配的补偿电流，该电流流经处于永磁场中的线圈，产生与被测物重力大小相等、方向相反的电磁力，驱动杠杆系统快速恢复至平衡状态。由于补偿电流的大小与被测物的质量呈严格的线性对应关系，通过精准测量该补偿电流的数值，即可快速、准确计算出被测物的实际质量。

核心功能与合规实战价值

设备采用专利一体连杆式电磁力平衡传感器，配合优化的抗干扰电路与进口核心元件，在 500g 最大称量范围内实现了 1mg 的实际分度值，在线性误差、称量重复性、环境抗干扰能力方面表现优异，可有效抵御法医实验室中离心机、PCR 仪、质谱仪等设备产生的复杂电磁干扰，确保在实验室常规运行环境下仍能输出稳定、可靠的称量数据，哪怕是微量的标准品、珍贵涉案物证，也能实现精准计量。

设备内置全功能称量模式，除基础称量功能外，还具备全量程去皮、置零、百分比称量、计件称量、累计称量及多单位转换等丰富功能，可全面适配法医实验室多样化的称量需求，包括微量标准品的精准点数、系列标准溶液的累计添加、不同体系的单位换算等场景，高对比度液晶显示屏与直观的操作界面，可大幅降低操作门槛，提升实验室日常工作效率。

设备搭载智能自检与全流程故障预警系统，开机即执行全性能自动自检，可对超载、欠载、传感器运行状态、秤盘安装情况、环境振动干扰、称量准确度超差、校准数据错误等异常情况进行自动诊断与声光报警，可有效预防因设备状态异常导致的实验误差，甚至珍贵、不可复现涉案检材的损毁，全程保障司法鉴定检材的安全与检验流程的合规性。

设备标配 RS232 标准通信接口，可直接连接实验室微型打印机或计算机终端，实现称量数据的实时记录、自动打印与批量导出存档，可与实验室 LIMS 信息管理系统无缝对接，完整留存每一次称量的原始数据、操作时间、操作人员信息，完全满足 CNAS 实验室认可、司法鉴定机构资质认定对检验原始数据全流程可追溯的严格要求，从计量源头保障涉案物证检验全流程的证据链完整、可复核，确保检验结果具备完整的司法证据效力。同时设备可选配密度测试组件，可扩展实现固体、液体样本的密度精准测定，适配工具痕迹、微量物证材料分析的多元化检验需求。

合规应用场景

本设备仅可在具备法定检验资质的刑事技术实验室、司法鉴定机构内，由经过计量操作专业培训的人员规范使用，核心合规应用场景包括五大类：一是毒物、毒品定量分析，用于涉案毒（药）物标准品、内标物的精准称量，以及待测血液、组织粉末、剩余食物等生物检材的重量计量，为标准曲线构建、添加回收率计算、检材中毒物绝对含量测定提供核心计量数据，支撑投毒、吸毒、药物过量致死等案件的定性定量鉴定；二是法医 DNA 检验试剂配制，用于 TAE/TBE 缓冲盐、琼脂糖、蛋白酶 K、Chelex-100 等 DNA 提取、扩增、电泳关键试剂的精准称量，保障 PCR 反应体系、电泳缓冲液的浓度一致性与稳定性，是获得稳定、可重复 STR 分型结果的核心前提；三是微量物证与文痕检验，对案件现场提取的纤维、油漆碎片、墨粉、油墨、文书篡改添加的微量物质、爆炸残留物等微量物证进行精确称重，为后续成分分析、种类比对提供量化依据，同时可用于涉案微量物证的总量评估；四是工具痕迹与材料分析，在工具痕迹比对检验中，对疑似作案工具上脱落的金属微粒、现场提取的金属碎屑、塑料碎片进行精准称量，配合密度测试组件完成材料密度测定，辅助实现作案工具的种类认定与同一比对；五是实验室质量管理体系建设，用于实验室移液器、容量瓶、分度吸量管等计量器具的定期容量校准（通过纯化水重量法），以及各类精确浓度标准溶液、缓冲体系、质控样品的制备，支撑刑事技术实验室计量体系的合规、稳定运行。

核心技术参数

本产品采用专利一体连杆式电磁力平衡传感器，最大称量量程 500g，实际分度值 1mg，具备全量程去皮、置零、百分比称量、计件称量、累计称量、单位转换、外部自动校准等核心功能。设备配备高对比度液晶显示屏，标配 RS232 标准通信接口，波特率 1200，可实现称量数据的实时传输、打印与导出。内置开机全性能自检程序，可对超载、欠载、传感器损伤、环境干扰、准确度超差、校准错误等多种异常情况进行自动诊断与声光报警。整机重量约 7kg，机身配置水平仪与可调节地脚，标配下称钩，可选配密度测试组件扩展应用功能。

合规实战应用案例

某市公安局刑事技术支队受理一起重大投毒杀人案件，受害人因饮用被投毒的饮用水后中毒身亡，法医提取了受害人的血液、尿液、胃内容物，以及现场剩余的饮用水、水杯擦拭物等涉案检材，需要通过液相色谱 - 质谱联用技术完成毒物的定性定量分析，为案件诉讼提供具备法律效力的鉴定意见。由于涉案检材中毒物含量极低，标准溶液配制、检材前处理的称量精度直接决定了定量结果的准确性与司法有效性。检验人员使用本法医实验室精密电子天平，严格按照计量规范完成了毒物标准品、内标物的精准称量，配制了梯度浓度的标准系列溶液，同时完成了待测检材的精准定量取样，全程通过 RS232 接口同步留存了所有称量的原始数据，确保了标准曲线的线性相关系数符合检验规范要求，最终成功在检材中检出剧毒除草剂成分，并完成了精准的定量分析，出具的司法鉴定意见被法庭全部采纳，为案件的定罪量刑提供了核心科学证据，本设备的高精度称量能力、数据可追溯设计，为本次鉴定工作的合规性、准确性提供了关键基础保障。
某市发生系列入室盗窃案件，犯罪嫌疑人采用技术开锁方式入室作案，现场仅提取到了嫌疑人遗留在锁芯内的微量金属碎屑、油漆碎片，以及门窗把手处的纤维物证，均为微量疑难物证，需要通过理化检验完成物证的种类认定与溯源。检验人员使用本精密电子天平，对多份微量金属碎屑、油漆碎片、纤维物证进行了精准称量，确保了后续裂解、提取、仪器分析的样本量一致性，通过精准的称量数据完成了物证成分的定量分析，最终明确了金属碎屑的材质型号、油漆碎片的成分体系、纤维的种类与生产批次，为侦查人员锁定作案工具、排查嫌疑人员提供了关键的量化依据。侦查人员根据微量物证的检验结果，成功锁定了有多次盗窃前科的嫌疑人刘某某，在其住处查获了匹配的作案工具与剩余油漆、金属材料，破获了该系列跨区域入室盗窃案件 30 余起，本设备的毫克级高精度称量能力，为微量物证的成功检验与案件侦破提供了不可或缺的技术支撑。

厂家信息‌：北京毕思特联合科技有限公司

网址：https://www.bestlh.com

‌地址‌：北京市亦庄开发区经海六路一号院尖子班 C9 独栋

‌电话‌：010-56526048

Application Introduction of Forensic Laboratory Precision Electronic Balance (Electromagnetic Force Compensation Type)

Global site URL：https://xilankeji.en.alibaba.com

【Important Compliance Pre-Declaration】This equipment is a legal metrological instrument dedicated to forensic laboratories and criminal technical inspection. It is only developed, produced and sold for state organs and authorized authentication institutions with legal qualifications of forensic material evidence identification, toxic and drug analysis, and trace evidence inspection, including public security organs, procuratorates, judicial administrative organs, and judicial authentication institutions, and will not be provided to any individual, unqualified enterprise or non-authorized unit. The installation, use, calibration and maintenance of this equipment must strictly abide by national laws, regulations and metrological specifications such as the Metrology Law of the People's Republic of China, Criminal Procedure Law of the People's Republic of China, General Rules for Judicial Authentication Procedures of the People's Republic of China, Forensic Science DNA Laboratory Specification, Criteria for the Accreditation of Laboratory Competence and JJG 1036-2022 Electronic Balance National Metrological Verification Regulation. It must be operated in a standardized manner by laboratory technicians who have received professional training, and the legal metrological verification and performance verification must be completed on schedule. It is strictly prohibited for unqualified personnel to use it in violation of regulations, and it is strictly prohibited to cause damage to involved evidence, distortion of test data and invalidation of judicial authentication evidence due to metrological inaccuracy and improper operation.

Product Overview

The Forensic Laboratory Precision Electronic Balance (Electromagnetic Force Compensation Type) is a professional weighing and metering instrument built based on a high-precision electromagnetic force compensation sensor, which is deeply customized for the accurate quality measurement needs of involved evidence, samples and experimental reagents in criminal science and technology laboratories. The core value of this equipment is to provide high-precision and high-stability quality measurement data at the milligram level for key judicial identification links such as forensic toxicological quantitative analysis, DNA test reagent preparation, trace evidence physical and chemical inspection, and standard solution preparation. The equipment integrates intelligent calibration, full-function weighing mode, complete fault self-diagnosis system and traceable data management function, which can ensure the accuracy, traceability and reliability of metrological data in the whole process from involved sample preparation to test data analysis. It is the core basic metrological guarantee equipment to maintain the scientificity, impartiality of judicial authentication and the legal effect of evidence.

Technical Principle

This balance adopts the patented integrated connecting rod type electromagnetic force compensation sensor technology, which realizes high-precision quality measurement based on the physical principle of balance between electromagnetic force and gravity. It completely avoids the friction loss and precision attenuation of traditional mechanical balances, and has the core advantages of high sensitivity, fast response and excellent long-term stability, which perfectly adapts to the weighing needs of trace and precious involved evidence in forensic laboratories. When the measured object is placed on the weighing pan, its gravity will drive the lever system of the sensor to produce accurate displacement. The displacement is captured in real time by the high-precision position detector and converted into an electrical signal, which is synchronously fed back to the closed-loop control circuit. The control circuit then generates a compensation current that accurately matches the gravity. This current flows through the coil in the permanent magnetic field, and generates an electromagnetic force equal in magnitude and opposite in direction to the gravity of the measured object, driving the lever system to quickly return to the balanced state. Since the magnitude of the compensation current has a strict linear corresponding relationship with the mass of the measured object, the actual mass of the measured object can be calculated quickly and accurately by precisely measuring the value of the compensation current.

Core Functions and Compliance Practical Value

The equipment adopts a patented integrated connecting rod type electromagnetic force compensation sensor, matched with an optimized anti-interference circuit and imported core components, and achieves an actual division value of 1mg within the maximum weighing range of 500g. It has excellent performance in linear error, weighing repeatability and environmental anti-interference ability, and can effectively resist the complex electromagnetic interference generated by centrifuges, PCR instruments, mass spectrometers and other equipment in the forensic laboratory, ensuring stable and reliable weighing data output even under the conventional operating environment of the laboratory. Even trace standard products and precious involved evidence can achieve accurate measurement.

The equipment has a built-in full-function weighing mode. In addition to the basic weighing function, it also has rich functions such as full-range tare, zero setting, percentage weighing, counting weighing, cumulative weighing and multi-unit conversion, which can fully adapt to the diversified weighing needs of forensic laboratories, including accurate counting of trace standard products, cumulative addition of series standard solutions, unit conversion of different systems and other scenarios. The high-contrast liquid crystal display and intuitive operation interface can greatly reduce the operation threshold and improve the daily work efficiency of the laboratory.

The equipment is equipped with an intelligent self-inspection and full-process fault early warning system. It performs full-performance automatic self-inspection when starting up, and can automatically diagnose and give an audible and visual alarm for abnormal conditions such as overload, underload, sensor operating status, weighing pan installation, environmental vibration interference, weighing accuracy out of tolerance, and calibration data error. It can effectively prevent experimental errors caused by abnormal equipment status, and even damage to precious and non-reproducible involved evidence, ensuring the safety of judicial authentication evidence and the compliance of the inspection process throughout the process.

The equipment is equipped with a standard RS232 communication interface as standard, which can be directly connected to the laboratory micro printer or computer terminal to realize real-time recording, automatic printing and batch export and archiving of weighing data. It can be seamlessly connected with the laboratory LIMS information management system, and completely retain the original data, operation time and operator information of each weighing, which fully meets the strict requirements of CNAS laboratory accreditation and judicial authentication institution qualification accreditation for the full traceability of test original data. It ensures the integrity and reviewability of the evidence chain in the whole process of involved evidence inspection from the metrological source, and ensures that the test results have complete judicial evidence validity. At the same time, the equipment can be optionally equipped with a density test component, which can expand the accurate density measurement of solid and liquid samples, and adapt to the diversified inspection needs of tool marks and trace evidence material analysis.

Compliant Application Scenarios

This equipment can only be used in a standardized manner by personnel professionally trained in metrological operation in criminal technology laboratories and judicial authentication institutions with statutory inspection qualifications. The core compliant application scenarios include five categories: First, quantitative analysis of poisons and drugs, which is used for the accurate weighing of involved poison (drug) standard products and internal standard substances, as well as the weight measurement of biological samples such as blood, tissue powder and remaining food to be tested, providing core metrological data for the construction of standard curves, calculation of addition recovery rate and determination of absolute content of poisons in samples, and supporting the qualitative and quantitative identification of poisoning, drug use, drug overdose death cases. Second, the preparation of reagents for forensic DNA testing, which is used for the accurate weighing of key reagents such as TAE/TBE buffer salt, agarose, proteinase K, Chelex-100 for DNA extraction, amplification and electrophoresis, to ensure the concentration consistency and stability of PCR reaction system and electrophoresis buffer, which is the core premise to obtain stable and repeatable STR typing results. Third, trace evidence and document inspection, which carries out accurate weighing of fibers, paint fragments, toner, ink, trace substances added to tampered documents, explosion residues and other trace evidence extracted from the case scene, provides quantitative basis for subsequent component analysis and type comparison, and can also be used for the total amount assessment of involved trace evidence. Fourth, tool mark and material analysis, in the tool mark comparison inspection, it accurately weighs the metal particles falling off the suspected crime tool, the metal debris and plastic fragments extracted from the scene, and completes the material density measurement with the density test component, to assist in the type identification and identical comparison of the crime tool. Fifth, the construction of laboratory quality management system, which is used for the regular capacity calibration of metrological instruments such as pipettes, volumetric flasks and graduated pipettes in the laboratory (by purified water weight method), as well as the preparation of various standard solutions, buffer systems and quality control samples with accurate concentration, supporting the compliant and stable operation of the metrological system of criminal technology laboratories.

Core Technical Parameters

This product adopts a patented integrated connecting rod type electromagnetic force compensation sensor, with a maximum weighing range of 500g and an actual division value of 1mg. It has core functions such as full-range tare, zero setting, percentage weighing, counting weighing, cumulative weighing, unit conversion, and external automatic calibration. The equipment is equipped with a high-contrast liquid crystal display screen, and is equipped with a standard RS232 communication interface with a baud rate of 1200, which can realize real-time transmission, printing and export of weighing data. It has a built-in boot full-performance self-inspection program, which can automatically diagnose and give audible and visual alarms for various abnormal conditions such as overload, underload, sensor damage, environmental interference, accuracy out of tolerance, and calibration errors. The whole machine weighs about 7kg, the body is equipped with a level meter and adjustable feet, a standard weighing hook under the body, and an optional density test component to expand the application function.

Practical Application Cases

The Criminal Technology Detachment of the Municipal Public Security Bureau accepted a major poisoning and homicide case. The victim died of poisoning after drinking poisoned drinking water. The forensic doctor extracted the victim's blood, urine, gastric contents, as well as the remaining drinking water and water cup wipes at the scene. It is necessary to complete the qualitative and quantitative analysis of the poison through liquid chromatography-mass spectrometry technology, to provide a judicial authentication opinion with legal effect for the case litigation. Because the content of the poison in the involved samples is extremely low, the weighing accuracy of standard solution preparation and sample pre-processing directly determines the accuracy and judicial validity of the quantitative results. The inspectors used this Forensic Laboratory Precision Electronic Balance, completed the accurate weighing of poison standard products and internal standard substances in strict accordance with metrological specifications, prepared a standard series solution with gradient concentration, and completed the accurate quantitative sampling of the tested samples at the same time. All the original data of weighing were retained synchronously through the RS232 interface throughout the process, ensuring that the linear correlation coefficient of the standard curve met the inspection specification requirements. Finally, the highly toxic herbicide components were successfully detected in the samples, and the accurate quantitative analysis was completed. The issued judicial authentication opinion was fully adopted by the court, providing core scientific evidence for the conviction and sentencing of the case. The high-precision weighing capacity and data traceable design of this equipment provided key basic support for the compliance and accuracy of this identification work.
A series of burglary cases occurred in a certain city. The suspect committed the crime by technical unlocking. Only trace metal debris and paint fragments left by the suspect in the lock cylinder, as well as fiber evidence at the door and window handles were extracted from the scene, all of which are trace and difficult evidence. It is necessary to complete the type identification and traceability of the evidence through physical and chemical inspection. The inspectors used this precision electronic balance to accurately weigh multiple pieces of trace metal debris, paint fragments and fiber evidence, ensuring the consistency of sample volume for subsequent cracking, extraction and instrumental analysis. The quantitative analysis of the evidence components was completed through accurate weighing data, and finally the material model of the metal debris, the component system of the paint fragments, the type and production batch of the fiber were clarified, which provided key quantitative basis for the investigators to lock the crime tools and screen the suspects. According to the inspection results of trace evidence, the investigators successfully locked the suspect Liu, who had many previous theft convictions, seized the matching crime tools, remaining paint and metal materials at his residence, and solved more than 30 cross-regional burglary cases in this series. The milligram-level high-precision weighing capacity of this equipment provided an indispensable technical support for the successful inspection of trace evidence and the detection of the case.