Solution for the automatic determination of benzene crystal point

September 15, 2020

The crystal point detection of benzene is a characteristic index of the purity test of general industrial products.
In the low temperature cooling process, the pure liquid may appear too cold state, namely when at or below the temperature of crystallization point, the material is still in a liquid state without precipitation crystallization to coagulation state, the main reason is due to the static in the liquid, no enough seed formation, although reach even below the crystallization temperature at this moment, but not in crystallization.
When there is proper stirring in the system, as the cooling process goes on, enough crystal species appear to promote crystal formation.
Therefore, when determining the crystal point of benzene, it will be clearly stated during the operation process that the cooling operation is carried out, and the liquid of benzene sample is properly stirred.
If there is no stirring, the measured value will be low, and the temperature may increase abnormally during the measuring process.
SH406B automatic benzene crystallization point analyzer is applicable to the standard GB/T3145-1982 benzene crystallization point determination, GB/T 3069.2-2005 naphthalene crystallization point determination, GB/T 3710-2009 industrial phenol, phenol crystallization point determination, GB/T7533-1993-2005 organic chemical products crystallization point determination, GB/T618-2006 chemical reagent crystallization point determination.
Determination of crystallization point of plasticizers.
(Benzene crystallization point meter, phenol crystallization point meter, phenol crystallization point meter, freezing point meter, plasticizer crystallization point meter)
Instrument features: embedded system design, the whole test process automatic detection;
Imported PT100 sensor and imported temperature control system are adopted.
Color touch screen;
The test results can be stored;
You can view the historical data;
The results can be printed on the instrument and automatically stirred mechanically. The experimental results can be exported through the USB flash disk. After being stored in the computer, the experimental results can be compared for many times.
Apparatus needed for experiment
1.SH406B benzene crystal point automatic tester, developed and produced by Shandong Shengtai Instrument Co., LTD.
2. Conform to GB/T3145.

Experimental steps:
Preparation work
1. After unpacking the instrument, please count the accessories according to the packing list. If there is any damage, please contact our company.
2. The instrument should be handled vertically. The tilt Angle should not exceed 30 degrees along the height of the instrument.
3. Connect the power supply of the instrument to the socket with a capacity of 220V/10A or above, and pay attention to having a good grounding wire.
Ii. Experiment process
1. After unpacking the instrument, please count the accessories according to the packing list. If there is any damage, please contact our company.
2. The instrument should be handled vertically. The tilt Angle should not exceed 30 degrees along the height of the instrument.
3. Before starting the machine (alcohol should be added for the first time), check the alcohol level in the cold bath to ensure that the alcohol level is higher than the refrigeration circuit and the liquid level of the sample in the cold bath. When the alcohol is insufficient, be sure to add enough alcohol first and then conduct the experiment.
4. Connect the power supply of the instrument to the socket with a capacity of 220V/10A or above, and pay attention to having a good grounding wire.
5. Take out the sample and put it into a clean and dry cooling pipe.
6. Place the cooling tube in the coolant and tighten the cork.
7. Adjust the proper position of the test-tube agitator so that the sensor is in the center of the circle of the agitator.
8. Turn on the power and click the touch screen to enter the main control interface.
The main display area is the trend chart of the temperature change of the sample over time, which can show the temperature value of the sample and the ice bath. The display area on the right will show the specific value, and the experimental results of the expected crystallization point and the test tube are shown below.
On the lower right are the start and close buttons.
Date and time can be set on the parameter setting interface to conduct temperature calibration for sample temperature and bath temperature.
And the sample number can be set.
If these parameters are modified, the virtual keypad will appear in the click time number and click length box to complete the modification of the number.
The expected crystal point is related to the experimental process. The instrument detects the crystal point from 15° above the expected crystal point and records it every 15S until the crystal point is detected.
If the crystal point has not been detected by the expected crystal point, the instrument can be extended to 30 degrees below the expected crystal point and continue to detect, leaving a large range for the convenience of users.
Bath temperature control is also related to the expected crystallization point (bath heating beyond the range)