Testing principle and selection of melting point and melting rate tester
Release time:
2022-12-27
The melting point is the equilibrium temperature of a solid and liquid substance under atmospheric pressure, measured by the temperature increase of a crystalline substance from solid to liquid, and is recorded as the melting point. The melting point is an important method for identifying substances and determining the purity of substances. Therefore, Melting Point and Melting Rate Tester It plays an important role in the chemical industry and medical research. Pure solid substances generally have a fixed melting point and a short melting range, generally not exceeding 0.5-1℃, which can be used to determine the purity of the substance and identify unknown substances. Mix the unknown substance with the known substance and measure the melting point. If the melting point does not change, and the melting point range does not exceed 1℃, it can usually be considered that the two are the same substance. This method is called the mixed melting point method.
At this stage, the main method for testing the melting point is to use a melting point apparatus for measurement. The manufacturing standard of the melting point and melting rate tester is the national standard JJG 701-2008 verification procedure. Melting point apparatuses are popular with users for their simple operation and clear results, especially fully automatic melting point apparatuses that do not require laboratory personnel to monitor them at all times.
There are many types and brands of melting point apparatuses on the market today. The following aspects can be referred to when choosing a suitable melting point and melting rate tester:
1. Sample testing conditions: Powder samples can use a melting point apparatus based on capillary melting point measurement, and visual or automatic melting point apparatuses can determine specific indicators such as whether the sample is transparent after melting, the initial melting of the sample, and the melting range. For flake or block samples, a micro melting point apparatus can be used.
2. Testing accuracy, repeatability of test results, and testing range are references for selecting a melting point apparatus. According to actual needs, the higher the accuracy and repeatability, the better after meeting the measurement range.
3. Verification of the melting point apparatus: The melting point apparatus needs to be verified after power-on use or after one year of use. Due to the large error caused by long-term use and seasonal temperature differences, verification is also carried out once a year.
According to different needs, send it to the relevant department for calibration, and the department will issue a report based on the calibration results; if the results do not require a report from the relevant authoritative department, the instrument can also be sent back to the purchasing company for calibration; or self-calibration can be performed according to the calibration procedure and purchased standards. The melting point apparatus has calibration settings, and operations are performed according to the settings and standards.
Precautions for the use of melting point and melting rate testers:
1. The melting point apparatus should be placed in a dry, dust-free, and ventilated laboratory environment to avoid excessive humidity and dust pollution, which reduces the service life of the melting point apparatus. The principle of the instrument is acid, alkali, and other corrosive liquids;
2. When sampling with a capillary tube, pay attention to avoid capillary breakage and hand injury. If the sample to be tested produces toxic gases after decomposition, the instrument should be placed in a ventilated kitchen for testing. During the experiment, avoid contact with the heating parts to prevent burns;
3. After using the instrument, the temperature drops to room temperature. Before using the instrument, check whether the tube sleeve is assembled well with the furnace body; check whether the light source output is good.
Related Blog
Scan
Luoyang Turner High Temperature Instrument Co., Ltd.
+86-400-880-7095
Sales (same as WeChat):18695992058
Contact:+86-379-69755886
Address: South Section of Shuangxiang Road, Luoxin Industrial Cluster, Luoyang City, Henan Province
Email:tnkinstrument@163.com
Copyright © Luoyang Tainake High-Temperature Instrument Equipment Co., Ltd. IPV6