键控触发温度标注显微熔点仪研制

显微熔点仪在材料熔点测定、药物鉴别、煤灰熔融性分析等医药化工领域具有重要的应用价值。针对操作者观察熔化状态与记录温度不能同时进行的特点,开发了通过按键触发记录熔化温度的新型熔点仪。考虑恒温控制过程中温度会出现振荡的特性,提出了按设定升温速率动态调整目标温度的分段所列积分微分控制程序,方便操作者在上位机进行自由设定。键控触发时间与温度数据通过RS-485串行通信接口,以Modbus RTU协议格式上传至上位机。以纯磺胺为标准样,实测结果验证了该熔点仪的可行性与准确性。相较于传统显微熔点仪,键控触发温度标注显微熔点仪在操作难度、结果精度等方面更具先进性。

Development of Microscopic Melting Point Instrument with Temperature Labeling by Key Triggering

Microscopic melting point meter is widely used in the fields of medical and chemical industries,such as the determination of material melting point,verification of drugs and the analysis of the fusibility of coal ash,etc.The measurement accuracy is reduced by the time difference between observing the melting state of the material under the microscope and reading the temperature indication during the measurement.High precision measurements require two people to cooperate to complete the operation.In order to solve the above problems,a new melting point instrument is developed which records the observed temperature indication by clicking the button.The temperature control apparatus dynamically adjusts the target temperature according to the set heating rate.The upper computer designs different proportion integration differentiation(PID)parameters of the heating program for sections to prevent the temperature from oscillating.The keying trigger time and temperature data are uploaded to the upper computer in Modbus RTU protocol format through RS-485 serial communication interface.Taking pure sulfonamide as standard sample,the feasibility and accuracy of the instrument were verified by the measured results.Compared with the traditional micro melting point instrument,the key trigger temperature labeling micro melting point instrument is more advanced in terms of operation difficulty and accuracy.