Use and maintenance of respiratory dust sampler

Use and maintenance of respiratory dust sampler 1. Sampling:

Use an appropriate hose to connect the air inlet on the back of the instrument to the sampled load. Press the ON key to turn on the instrument. Press the “OK/Cancel” button on the microcomputer. The display shows “0:00” and then presses the “Point” button. Select the required time, the maximum time for this key is 59 points, if 59 minutes is not enough, then press the "hour" button, the maximum time for this key is 99 hours, when the time is selected, press the "OK/Cancel" button to start sampling. The computer enters the countdown state while the sampling pump is working. When the computer display shows "0:00", the host computer ends the sampling. If you need to sample again, set the time again to continue sampling. If you do not need to sample, press the key to OFF to turn off the instrument. The computer enters the countdown state while the sampling pump is working. When the computer display shows “0:00”, the host computer is automatically controlled by the computer program to cut off the power. If you want to reset or shut down in advance, just press and hold the “OK/Cancel” button to enter the reset or shutdown mode. The display shows “0:00”. When using a respiratory dust sampling head, a Φ25mm colorless glass plate (impact plate) shall be installed and silicone oil shall be applied. When the sampling flow rate is 20L/min, the characteristics of the sampling head sorting device conform to the “BMPC” curve standard. The level trapping efficiency is ≥7.07 microns for 100%, 5 microns for 50%, and 2.2 microns for 10%.

2. Calculation:

The concentration of respiratory dust in the air is calculated as follows. R = [(m2-m1) ÷ Qt] × 1000 where:

R - Respiratory dust concentration in air, mg/m3;

M2—filtered mass after sampling, mg;

M1 - the quality of the filter before sampling, mg;

Q - sampling flow, L/min;

t - sampling time, min.

The dust concentration in the air is calculated as follows: C=[(m2-m1)÷Qt]×1000

Where: C - dust concentration in the air, mg/m3;

M2—filtered mass after sampling, mg;

M1 - mass of the membrane before sampling, mg,

Q - sampling flow, L/min;

t - sampling duration, min.

Note: When collecting respiratory dust, the sampling flow must be constant at 20L/min to ensure that the dust particle classification meets the requirements of the BMRC separation curve.

3, charge:

Plug the AC power cord into the 220V AC input of the instrument and the power supply. The instrument is in the off state. It takes about 14 to 16 hours (standard charging time) for a full charge. Each time sufficient electricity can work continuously or cumulative work for about 3 hours.

The battery voltage at the time of sampling indicated by the voltmeter at the time of sampling, and the battery voltage at the charge indicated at the time of charging. The full electric voltmeter indicates about 12V.

Respiratory dust sampler precautions:

1, should be placed in a ventilated and dry place for a long time. If not more than 3 months should be added to ensure that the life of high-energy nickel-metal hydride batteries.

2. In the dusty air, the sampling head with filter membrane should be installed before starting the machine. Otherwise, the dust particles enter the machine and affect the operation of the air pump and the cleanliness of the airway.