Automatic vapor pressure tester (Reid method)

After the automatic vapor pressure tester (Reid method) is turned on, the system will automatically turn on the circulating water pump, connect the heater, start heating the water bath, and control the temperature of the water bath to remain constant at 37.8 ° C; 0.1 ℃. Users should process the samples and assemble the steam pressure cartridge according to standard requirements, and then place them in the cartridge slot of the water bath; If "Start" is selected, the vapor pressure bomb will rotate back and forth at an angle of 350 degrees, and the system will automatically detect the pressure data in the three vapor pressure bombs until all three pressure data remain unchanged for two consecutive minutes. This pressure value will be used as the vapor pressure of the tested oil sample.

The automatic vapor pressure tester complies with the national standard GB/T8017 and is suitable for measuring the vapor pressure of gasoline. It can also be used to measure the saturated vapor pressure of volatile original and other volatile non viscous petroleum products.

After the automatic vapor pressure tester is turned on, the system will automatically turn on the circulating water pump, connect the heater, start heating the water bath, and control the temperature of the water bath to be constant at 37.8 ± 0.1 ℃. Users should process the samples and assemble the steam pressure cartridge according to standard requirements, and then place them in the cartridge slot of the water bath; If "Start" is selected, the vapor pressure bomb will rotate back and forth at an angle of 350 degrees, and the system will automatically detect the pressure data in the three vapor pressure bombs until all three pressure data remain unchanged for two consecutive minutes. This pressure value will be used as the vapor pressure of the tested oil sample.

The automatic vapor pressure measuring instrument adopts modern advanced technology, integrating mechanical, electronic and computer technology, and has a compact structure. Fully automated temperature control with accurate PID control accuracy up to 0.1 ℃, as well as PID automatic control, LCD display, gas-liquid chamber ratio of 1:4, automatic storage, automatic printing, pressure range of 0-160kpa, automatic pressure judgment function, automatic output of experimental results after stable pressure, all stainless steel vapor pressure bomb, quick connector connection, convenient and reliable gas path connection. Automatic rotation angle of 350 °, automatic direction change, large circulation mixing pump ensures consistent temperature in all parts of the bath. Stainless steel bath, ensuring uniform temperature inside the bath, digital display of pressure and bath temperature, with correction and calibration functions, and fault alarm.

The automatic vapor pressure gauge abandons the double chamber structure of the Reid method and adopts a micro, closed testing chamber and absolute pressure measurement principle. There are two main mainstream technologies:

1. Expansion method (mainstream technology, in accordance with ASTM D5191)

This is the technology currently in use.

Core principle: Inject a small amount of sample into a constant temperature test chamber with a known volume, causing partial evaporation and forming gas-liquid two-phase. Calculate the vapor pressure of the sample by measuring the volume expansion caused by sample evaporation, or by injecting inert gas (such as air) into the system to maintain the original volume at the required pressure.

Process description:

Injection and sealing: The instrument automatically inhales 1-5 mL of sample, injects and seals it in a testing chamber at a constant temperature of 37.8 ° C.

Establish equilibrium: The sample evaporates rapidly and the pressure inside the chamber increases.

Volume expansion or pressure compensation:

Expansion method: Measure the total volume expansion of a gas-liquid mixture.

Injection method: Inject dry air into the chamber to restore the volume of the gas-liquid mixture to its initial value, and the absolute pressure measured at this time is the vapor pressure of the sample.

Calculation and reporting: The built-in algorithm of the instrument automatically calculates and reports the vapor pressure results based on parameters such as pressure, temperature, and volume, and usually automatically corrects to dry vapor pressure (DVPE).

2. Micro method

The principle is more direct, using smaller amounts of samples.

Core principle: Inject a small amount of sample (about 0.1-0.2 mL) into a constant temperature test ball that has been evacuated and has a known volume. The sample evaporates instantly, and the equilibrium pressure generated is directly measured by a high-precision absolute pressure sensor, and then the vapor pressure of the sample is calculated.

Core structure composition of the instrument

Constant temperature test chamber/test ball: core reaction zone, precise temperature control at 37.8 ° C ± 0.1 ° C.

High precision absolute pressure sensor: directly measuring the absolute pressure within the system is the foundation of accurate data.

Automatic sampling system: can be connected to an automatic sampler to achieve batch continuous testing.

Gas path control system: used for vacuuming, injecting inert gases (such as dry air), and cleaning and blowing.

Precision temperature control system: Ensure constant temperature in the testing chamber and sample tubing.

Central Processing Unit and Intelligent Software:

Control all testing processes (injection, sealing, balancing, measurement, cleaning).

Collect pressure and temperature data, perform calculations and corrections.

Store data, generate reports, and enable online transmission.

Characteristics of Automatic Vapor Pressure Tester (Reid Method):

1. Automation level: Industrial grade ARM 32-bit chip core processor, automatically completes the testing process. The data can be exported through a USB flash drive and processed by a computer for environmentally friendly office and paperless testing.

2. Control system: Industrial grade PLC programmable logic controller is used, which has been treated with three proof paint to ensure worry free operation of the instrument. The 7-inch tablet has a touch screen display, and you can complete the experiment according to the screen prompts without training.

3. Operating system: Windows CE embedded operating system, with a fully Chinese operating interface, allowing for easy switching of pages, simple and convenient operation, automatic printing of results, and a large capacity storage function that can store tens of thousands of data and curves.

4. Safety performance: automatic diagnosis, over temperature alarm and automatic cut-off of heater power supply, and alarm prompt function for test completion.

5. Data input/output: RS485 connection standard, can be connected to USB 2.0 interface. Support online monitoring and downloading, making it more convenient to use.

Technical specifications of automatic vapor pressure tester (Reid method):

1. Power supply: AC220V ± 10% 50Hz

2. Power supply: 2000W

3. Environmental temperature: 10 ℃~30 ℃

4. Motor: 25W

5. Temperature range: Room temperature~50 ℃

6. Temperature control accuracy: 37.8 ℃± 0.1 ℃

7. Pressure range: gauge pressure 0~200kpa sensor: Ptl00

8. This instrument is designed for two rounds and can measure two samples simultaneously

9. The automatic rotation angle of the instrument is 350 °

10. Dimensions: 970 * 400 * 560mm