Resistance dry microbe penetration tester

Numerous examples have shown that bacteria penetrate shielding materials, such as bacteria-carrying dander or cleaning clothes, with dry organic or inorganic particles, or through packaging materials during storage. This instrument can be used to measure bacterial penetration on dry particles within the range of human dander size.

1. Test the principle

The tests were carried out on separate specimens fixed to a container. Among the containers, five contained bacillus subtilis talcum powder and one contained uninfected talcum powder as a control. A petri dish was inserted into the bottom of each container close to the bottom of the specimen.

The device that supports the container is oscillated by a gas-ball oscillator, in which the talcum powder that penetrates the specimen falls onto the petri dish, which is taken out and cultured.

Count growing colonies.

Technical specifications

1. Test chamber: black inner wall, volume: 0.5m3, built-in row fan and lighting;

2. Instrument air source: 0.8mpa compressed air;

3. Noise: about 90dB;

4. Touch screen operation;

5. Instrument size: 1000mm 690mm 1390mm;

6. Instrument weight: 85kg

7. Power supply: 220V.

Configuration list

This instrument should be carefully unpacked and inspected. Please contact our customer service department for any damage or loss of the instrument.

When you open the package, please check the following materials (subject to the actual packing list) :

1. 1 main engine;

2. 8 sets of test boxes;

3. Power cord 1 heel;

4. One copy of instruction manual

5. Optional accessories:

6. Air storage tank

2. Test criteria

The dry resistance microbial penetration tester was used to test the samples according to ISO 22612, YY/T 5056.5 test standards.

3. Composition and use of the instrument

The instrument is completed in strict accordance with the standard drawing, and fully meets and can achieve the test content required by the standard.

The instrument contains:

(1) pneumatic ball oscillator: the external air source through the pneumatic ball oscillator, through the corresponding adjustment and correction to keep the vibration frequency at the target frequency. It produces 20,800 vibrations per minute at a force of 650N.

(2) compressed air flowmeter: it is mainly used to measure the airflow that generates the vibration frequency of 20800(347Hz) times per minute.

(3) test container: the instrument has 6 stainless steel test containers with metal pistons on the top. The metal piston can be inserted 10mm below the cover through the central hole on the cover to ensure that the specimen does not relax. At the same time, each container has a narrow opening at the bottom of the attachment, which is used to insert petri dishes.

(4) marble slab: marble with an area of 400mm*400mm and a thickness of 10mm is used as the operating platform of the whole instrument.

(5) fixing plate: the stainless steel plate with 6 holes is fixed on the SLATE with a clamp for fixing and installing the test container

(6) rubber support: with 4 rubber supports, it is used to adjust the level, fix the position of the instrument and prevent movement.

test

1. Analysis of test steps:

The test was carried out on separate specimens fixed to one vessel. Among these containers, 5 containers containing bacillus subtilis talcum powder were used as test group and 1 container containing uncontaminated talcum powder was used as control group. A petri dish was inserted at the bottom of each container close to the bottom of the specimen.

The device that supports the container is oscillated by a gas-ball oscillator, and all the talcum powder that penetrates the specimen falls onto the petri dish, which is taken out and cultured.

Count the number of growing colonies.

2. Equipment debugging:

Ensure that dry microbe penetration tester is operational.

(1) adjust the level

Adjust 4 rubber supports according to the level so that the instrument is in the horizontal position.

(2) adjust the frequency of gas ball oscillator

By adjusting the gas ball oscillator to 20800 vibrations per minute.

3. Sample preparation:

(1) cut 12 test pieces

The size of 12 samples is 200mm×200mm.

(2) sterilization

Sterilize the cut samples and test containers.

(3) fix test containers

The test container is fixed on the fixing plate by rubber ring, so that it is closely connected with the fixing plate and the bottom is against the SLATE.

(4) preparation of talcum powder

Talc powder containing AATCC 9372 bacillus subtilis spore should be prepared at a concentration of about 108CFU/g, and the preparation process was based on YY/T 50565-2009.

4. Start experimenting.

The specimen was removed by aseptic method and placed on the mouth of each test vessel.

The lid is fixed to the container by pushing down the piston so that the specimen is fixed to a controlled degree of relaxation.

Let's remove the piston. 0.5g±0.1g bacteria-contaminated talcum powder was added to the specimen through the piston port, and the sixth container was used as the control container to add bacteria-free talcum powder. Seal piston port with film.

Cover each container with a small plastic bag.

The petri dish was inserted through a slit at the bottom of each container. Close the slit with sticky tape.

At a frequency of 20,800 vibrations per minute for 30min.

Remove plastic bags and tape.

The cover of the petri dish was inserted through the slit, the dish was taken out and cultured at 35℃ for 24h.

Count the colonies formed. The effective sample should be a 0 reading control dish. Otherwise, the test should be suspended because of external pollution.

Repeat the above experiment steps.

Zui tested less than 2 groups, and calculated the arithmetic mean of 10 valid results, which was the final result of zui.

End of the test

When the experiment is over, ensure that the data have been recorded and adjust the voltage regulator knob on the adjustment panel to 0 scale. Turn off the instrument intake device, turn on the exhaust fan and lighting, and clean the surface of each sample box.

5. Maintenance

Keep instrument dry

To ensure the normal use of the instrument and extend its service life, please keep the instrument dry. And use in a relatively dry environment, avoid water droplets splash or condensation, so as not to damage the non-water resistant devices. If you do not use the instrument for a long time, please disconnect the power and air source.

Parts damaged

The internal starting oscillator of the instrument is a vulnerable part, which can reduce the accuracy of oscillation frequency when the starting life is reached. New parts are recommended at this time.

At the same time, if the marble slab is damaged, please replace the same specification of accessories in time.

Microbial safety

In order to prevent contamination of the test personnel and the test environment, the test personnel should have the operational basis of microbial culture. Follow lab operation instructions.