Gas transmittance measurement

This method is used to determine the amount of gas transmitted by pharmaceutical films or flakes
.

This method includes the differential pressure method and the fuel analysis method
.

The fuel analysis method is only suitable for detecting oxygen transmission
.

Gas permeability refers most to the volume
of gas that is much larger than the sample at a constant temperature and pressure difference, in an area and time when it is stable.

Usually expressed as a volume value at standard temperature and 1 standard atmospheric pressure, it is: cm3 / (mR-24h-0.
1 MPa).
The gas transmission coefficient refers to the volume
of gas that passes through the thickness of the sample at a constant temperature and pressure difference, at the time of stable transmission.

Usually expressed as a volume value at standard temperature and 1 standard atmospheric pressure, it is: cm'-cm/mR-24h -0.
1MPa).
Test environment, temperature: 23 °C 2 °C, relative humidity: 50% 5%GPT-203 Differential Pressure Method Gas Transmittance Tester The first method differential pressure method Pharmaceutical film or flake separates the low pressure chamber and the high pressure chamber, and the high pressure chamber is filled with a test gas of about 0.
1 MPa, and the volume of the low pressure chamber is known
.

After the test product is sealed, the air in the low-pressure chamber is pumped to near zero
value by a vacuum pump.

Measuring the pressure increment OF the low pressure chamber with a manometer can determine the amount of gas in time as a function of the passage of the test gas from the high pressure chamber through the sample to the low pressure chamber, but the initial stage
of the change in gas transmission speed with the time surface should be excluded.

Instrumentation differential pressure method gas transmission measuring instrument, mainly including the following parts
.

The ventilation chamber is composed of two parts, the upper and lower parts, when the person is loaded for the test product, the upper part is a high-pressure chamber, which is used to store the test gas and is equipped with a gas injection tube
.

The lower part is a low-pressure chamber for storing distant gases and determining the pressure difference
between the front and back during ventilation.

The high and low pressure chambers of the pressure measuring device should have a pressure measuring device, the sensitivity of the pressure measuring device of the high pressure chamber should not be less than 100Pa, and the sensitivity of the low pressure chamber pressure measuring device should not be less than 5Pa
.

The purity of the test gas should be greater than 99.
5%.
Unless otherwise specified, the measurement method selects 3 pieces of the suitable size of the test product with uniform thickness, no folds, creases, pinholes and other defects, and the proud mark on the side of the test gas facing the test gas is proudly marked, placed in a dryer under 23 °C and placed for more than 48 hours, and the thickness of the test product is measured separately with a suitable measuring tool, accurate to 0.
001mm, each piece is measured at least 5 points, and the arithmetic average is
taken.

Place the instrument on it and test
it.

To reject the nonlinear phase at the start of the test, a 10-minute pre-breathing test should be performed and the test should be continued until the change in the pressure difference remains constant over the same time interval to achieve stable transmission
.

T is the test temperature, K; D is the thickness of the sample, cm
.

The test results are expressed as the arithmetic average of the three offerings, and the difference between the measured value and the average value of each offering shall not exceed 10%
of the average taxi of the average, except for the high barrier performance test [gas transmission result less than or equal to 0.
5cm' /Km2-24h ·0.
1 MPa)].

The measured value of the high barrier performance test product shall not be greater than 0.
5cm3/Km2·24h -0.
1MPa).
The second method of fuel analysis (coulomb method) ISOBARIC-404- oxygen transmittance tester The test product divides the breathable chamber into two parts
.

One side of the sample is oxygenated, and the other @ nitrogen carrier gas
.

The oxygen from the test product enters the battery analyzer with the nitrogen carrier gas for a chemical reaction and generates a voltage that is proportional to the amount of oxygen passing through the battery analyzer over time
.

Instrument device fuel analysis method gas transmission measuring instrument, the instrument mainly includes the following parts
.

The ventilation chamber is composed of two parts, which should be equipped with a temperature measuring device, and also need to be equipped with suitable seals, and the test area of the test product is adjusted according to the test range, usually between
1 and 150cm2.

The carrier gas is usually nitrogen or a nitrogen-hydrogen mixture containing a certain ratio of hydrogen
.

The purity of the test gas should not be less than 99.
5%.
The fuel detector (coulomb meter) is sensitive to oxygen and has constant operating characteristics, and is used to measure the amount
of oxygen transmitted.

Unless otherwise specified, the measurement method selects 3 pieces of suitable size for the test product with uniform thickness, flatness, no folds, creases, pinholes and other defects, marks the side of the test product facing the test gas, places it in a dryer under 23 °C and 2 °C, places it for more than 48 hours, measures the thickness of the test product with a suitable gage, accurate to 0.
001mm, measures at least 5 points, and takes the arithmetic average
.

The test is placed in a breathable chamber and then the test is performed, and the test is completed
when the value displayed by the instrument has been stable for a period of time.

The test results are expressed as the arithmetic average of the three test offerings, except for the high barrier performance test product [gas transmission result less than or equal to 0.
5cm3 / (m3-24h · 0.
1 MPa)], the difference between the measured value of each test product and the average value shall not exceed 10%
of the average taxi.

The measured value of the high barrier performance test product shall not be greater than 0.
5cm'/(m'-24h·0.
1MPa)
each time.