Knowledge points to be mastered in the operation of dust particle counters

Knowledge points to be mastered in the operation of dust particle counters

The dust particle counter is an instrument for measuring the number and particle size distribution of dust particles per unit volume in a clean environment. It can be widely used in various provinces and municipalities drug testing institutes, blood centers, epidemic prevention stations, disease control centers, quality supervision institutes and other authoritative institutions, electronics industry, pharmaceutical workshops, semiconductor, optical or precision machining, plastics, painting, hospitals, environmental protection, Inspection companies and other research departments and scientific research departments. The light source of the instrument has two kinds of ordinary light source and laser light source. The common light source is an iodine-tungsten lamp, which has a large volume, high heat generation and short life, and needs to be preheated after starting up. The laser light source is a laser, which has small volume, high stability and long service life. It is often integrated with the detection chamber and the photodetector to form a sensor. Common laser sources are HeNe lasers and laser diodes. The laser dust particle counter using a common light source has a low response to a particle signal of 0.3 μm or less, and its signal amplitude is almost the same as the noise amplitude of the counter itself, and the signal is difficult to detect from the noise. Such instruments, although labeled with a channel of 0.3 [mu]m, are only suitable for the determination of particles larger than 0.3 [mu]m, especially above 0.5 [mu]m. Due to the good monochromaticity of the laser and the stable and stable light energy, the laser dust particle counter using the laser source has a high signal-to-noise ratio (SNR). Some of these instruments can detect 0.1 μm particles.

To operate the dust particle counter, you must have the following knowledge points:

1. When connecting an external printer or connecting an external temperature and humidity sensor, you need to turn off the counter first; when performing the printing operation, the printer must have printing paper, otherwise it will damage the print head;

2, should be used in a clean environment to prevent damage to the laser sensor;

3. When handling, it should be handled lightly and with less vibration and impact. Especially for desktop particle counters, be more careful to avoid damage to internal components;

4. The particle counter is mainly used to test the clean environment of the purification workshop. When the measured material has loose particle material, dust source and spray, it should be kept at least twelve inches away from the inlet pipe. In order to avoid contamination of the sensor and pipeline with the above particles and liquids;

5. No high pressure decompression equipment (such as high pressure diffuser) should not sample compressed air. All counters are designed to operate at one atmosphere. The working position and sampling port of the instrument should be in the same air pressure and the same temperature and humidity environment to ensure the normal operation of the instrument;

6. The aqueous solution or other liquid cannot enter the sensor from the inlet pipe;

7. When the inlet pipe is covered or blocked, do not start the dust particle counter;

8. It is forbidden to extract gases containing oily and corrosive substances, and do not measure mixed gases (such as hydrogen and oxygen) that may react. These gases may also explode in the counter, if the gas is measured with the manufacturer, obtain more information and then operate;

9. When sampling, avoid sampling the gas contaminated by the gas discharged from the dust particle counter itself.