Calibration of transmission window measurement

1、 Overview of JGT 382 Standard

The JG/T 382-2012 "Transfer Window" standard has been implemented since November 1, 2012, aiming to standardize the production, inspection, and use of transfer windows. This standard specifies the basic requirements for the size, structure, material, appearance, etc. of the transfer window in detail. At the same time, specific requirements are put forward for the testing and disinfection channels, high-efficiency filters, ultraviolet lamps, nozzle center wind speed, air exchange rate, cleanliness, airtightness, pressure difference and other key performance of the transfer window.

2、 Preparation before calibration

Before performing transfer window calibration, the following preparations need to be made:

1. Equipment preparation: Ensure that the required testing instruments for calibration, such as hot ball anemometers, dust particle counters, differential pressure gauges, photometers, etc., are complete and in good condition.

2. Environmental preparation: Calibration should be carried out in a clean and interference free environment to ensure the accuracy of the calibration results.

3. Personnel training: Calibration personnel should be familiar with the content and requirements of JGT 382 standard, and master the correct calibration methods and operating procedures.

3、 Calibration items and methods

1. Calibration of wind speed at the center of the nozzle

Measure the air velocity at the center of each nozzle using a hot ball anemometer. When testing, the measuring point should be located at the center of the nozzle outlet plane. For B3 type transfer windows, the wind speed at the center of each nozzle should be measured and the arithmetic mean should be calculated as the nozzle center wind speed.

2. Ventilation rate calibration

The number of air changes is an important indicator for measuring the air circulation performance of transfer windows. The calibration method is to evenly divide each air supply outlet into at least 6 equally sized squares or rectangles with side lengths not exceeding 200mm. Use a hot ball anemometer to measure the air supply velocity at the center of each square or rectangle, and use the arithmetic mean of the air speed at each measuring point as the average air supply outlet velocity. Then, calculate the air exchange rate based on the average wind speed of the air supply outlet, the total area of the air supply outlet, and the volume of the air supply area of the transfer window.

3. Cleanliness calibration

Cleanliness is an important reflection of the air quality inside windows. In transfer windows with air cleanliness requirements, cleanliness testing should be conducted under the condition that the air exchange rate is qualified. Before testing, the transfer window should be cleaned and wiped, and left to air for at least 1 hour. Then, place the sampling head of the dust particle counter at the center of the window channel through the dedicated detection hole on the transfer window wall panel, close the door of the transfer window tightly, and turn on the purification system of the transfer window. After the data is stable, count continuously for at least 3 times, with each count lasting at least 1 minute. Use the arithmetic mean of the 3 consecutive stable counts as the cleanliness of the transfer window.

4. Airtightness calibration

Airtightness is a key performance of transmission windows to prevent the spread of contaminated airflow. The airtightness of the E1 type transfer window is achieved by using smoke emission method. Observe whether there is visible smoke escaping from the windows, doors, and all gaps of the transfer window. The air tightness test of E2 type transmission window is conducted using pressure attenuation method, which reduces the pressure inside the transmission window to below -500Pa, then closes the sealing valve and stops the exhaust. Record the pressure difference changes within 20 minutes. If the pressure difference inside and outside the transmission window is greater than 250Pa, the airtightness meets the requirements.

5. Differential pressure calibration

Pressure difference is an important indicator for measuring the air pressure difference inside and outside the transmission window. Place the tested transmission window on the workbench, place the pressure measuring tube on the differential pressure gauge through the pressure measuring hole in the transmission window channel, clean the foreign objects on the sealing surface and sealing strip of the box, close the door of the transmission window tightly, turn on the air supply and exhaust device of the transmission window, and read the reading of the differential pressure gauge after stable operation.

6. High efficiency filter integrity calibration

The high-efficiency filter is the core component of the transfer window air purification system. The photometer scanning leak test is suitable for leak detection and sealing of high-efficiency filters. During calibration, a linear or logarithmic scale photometer should be used for scanning leak testing to ensure that the leakage rate of the high-efficiency filter does not exceed 0.01%.

4、 Calibration result judgment

According to the requirements of JGT 382 standard, after calibrating the various performance indicators of the transfer window, the calibration results need to be judged. If all performance indicators meet the standard requirements, the calibration of the transmission window is judged to be qualified; If one or more performance indicators do not meet the standard requirements, it is determined that the calibration of the transmission window is unqualified and corresponding adjustments or repairs need to be made.

V. Summary

As an important equipment for material transfer in clean rooms, the stability and accuracy of the performance of the transfer window have a significant impact on the production environment and product quality. Calibrating the transfer window according to JGT 382 standard can ensure that the transfer window meets design and usage requirements, improve production efficiency and product quality. Therefore, all relevant enterprises should attach importance to the calibration of the transmission window and strictly operate and judge according to the standard requirements.

Company Background Introduction:

Ze Heng The advantage of Huapu in metrology calibration, verification, and confirmation is that it focuses on providing quality control services for biopharmaceuticals. It is very familiar with some special instruments, and its main team comes from pharmaceutical companies and instrument manufacturers, who are familiar with instrument and GMP regulations. For example, our team has specially developed a fluorescence quantitative PCR instrument calibration device to replace imports, which greatly reduces the cost of fluorescence quantitative/qualitative PCR instrument calibration (far lower than other peers); We have developed an internal calibration protocol for the cell counter; Developed internal calibration procedures for cell recovery instruments; The calibration procedure of gel electrophoresis scanner was developed; We have developed integrated wireless probes for lower and higher temperatures required for temperature verification, reducing the cost of users using probes extensively and replacing imports; There are many more examples, as we all come from a biological background, we pay attention to the process requirements of every biological user, focus on biopharmaceutical instruments and equipment, and strive to "go with quality and do instrument and equipment quality control" in order to make biopharmaceuticals safer.

We work closely with other units in terms of services, including mandatory inspections, special inspections, or services that cannot be done, to help customers send and collect items on their behalf, saving time, effort, and convenience.

Ze Heng Huapu is a professional service provider dedicated to providing laboratory instrument calibration, instrument and equipment validation, and factory validation for the biopharmaceutical industry. We provide pharmaceutical clients with one-stop quality control outsourcing services for QC/QA/engineering/validation/production departments.