What is the crystallization point of pure benzene? With what test?
Crystallization point is one of the important physical constants of material. The crystallization point of pure material is fixed and unchanged, and if it contains impurities, the crystallization point is reduced. Therefore, the purity of material can be judged by measuring the crystallization point. The crystallization point of pure benzene is 5.53℃.
The average crystallization point of coking benzene in a factory is 4.84℃, indicating that the impurity content of coking benzene is high. Coking benzene samples were taken for chromatographic composition analysis, and the analysis results are shown in the figure below. The content of pure benzene is 98.16%, the content of impurities is 1.84%, and there are more than 13 kinds of impurities.
Applicable standards GB/T3145-1982 Determination of benzene crystallization point, GB/T 3069.2-2005 determination of naphthalene crystallization point, GB/T 3710-2009 determination of industrial phenol, phenol crystallization point, Determination of crystallization point of organic chemical products and determination of crystallization point of chemical reagents GB/T7533-1993-2005 Determination of crystallization point of plasticizer. (Benzene crystallization point meter, phenol crystallization point meter, phenol crystallization point meter, freezing point meter, plasticizer crystallization point meter)
Two, meet the standards:
1. Upgrade to 7-inch TFT color LCD display;
2, refrigeration mode: fully enclosed high efficiency refrigeration compressor.
3. Number of test groups: 1 group (2 groups can be customized).
4, detection method: imported PT100 temperature sensor
5, after the upgrade can store historical data, easy to query; At the same time can be equipped with USB output function.
6, standard micro printer automatic measurement and automatic printing
7. If there is no operator after the test, set the automatic closing time of the refrigerator within 0-50min to avoid the frequent opening of the compressor and prolong the service life of the instrument.
8, including laser printer interface, can be linked to HP1108 laser printer (optional).
9, with date password setting function.
10, standard micro printer automatic measurement automatic thermal printing
11, with TCP network transmission function
12. Limis system can be uploaded and connected
1, working power supply: AC220V±10%; 50 hz.
2. Working cold tank: double vacuum glass bath.
3, cold tank temperature control: +80℃ ~ -10℃.
4, temperature control accuracy: ±0.01℃.
5, bath liquid stirring: stirring motor automatic stirring, power 6W, 1200r/min.
6, refrigeration system: new refrigeration compressor.
7, sample stirring: synchronous reduction motor, 60 times/min.
8, ambient temperature: ≤30℃.
9, relative humidity: ≤85%.
10. Power consumption of the whole machine: about 1500W.