1Dust samplerPreparation before use

Equipment inspection

Battery/Power: Ensure that the device is fully charged. If long-term sampling is required, prepare a backup battery or an external power source.

Airtightness test: Install a blank filter membrane, set the flow rate, and block the air inlet. If the flow rate does not decrease to zero, it indicates a leak and the sealing ring or pipeline connection needs to be checked.

Flow calibration: Use standard flow meters (such as soap film flow meters) to calibrate equipment, ensuring that the error is within ± 5%, and record calibration data (date, set flow rate, actual measurement value, etc.).

Preparation of filter membrane

Select filter membrane: Choose suitable materials (such as glass fiber, polyvinyl chloride) based on the nature of the dust (such as total dust, respiratory dust).

Constant weight treatment: Place the filter membrane in a constant temperature and humidity chamber (temperature 20 ± 1 ℃, humidity 50 ± 5%) to balance for 24 hours, weigh it with a precision balance, and record the initial mass (accurate to 0.1mg).

Sampling point confirmation

Location selection: Fixed at the height of the worker's breathing belt (about 1.5 meters) during individual sampling; During fixed-point sampling, avoid obstacles and place it in the downwind direction of the dust spill source.

Environmental recording: Measure the temperature, humidity, and air pressure at the sampling point and record them.

2、 Sampling operation steps

Install filter membrane

Clean operation: Use tweezers to pick up the filter membrane in a dust-free environment, with the hair facing towards the intake direction, and insert it into the sampling clip to avoid touching the center area of the filter membrane.

Sealing inspection: Tighten the sealing ring of the sampling clip to ensure there are no wrinkles or damages.

connected device

Individual sampling: Fix the sampler at the collar of the operator, with the air inlet facing the breathing zone.

Fixed point sampling: Use a tripod to fix the sampler and maintain horizontal stability.

Parameter Settings

Flow rate setting: Set the sampling flow rate (usually 2L/min) according to standards (such as occupational health standards).

Time setting: Calculate the sampling time according to the formula:

For example, collecting 10L of air takes 5 minutes (flow rate 2L/min).

Start stop setting: Set automatic start stop time or manually control.

Start sampling

Observe flow rate: After starting, check if the flow rate is stable. If the fluctuation exceeds ± 10%, stop sampling and investigate the cause (such as pipeline blockage or membrane overload).

Regular inspection: Check the flow rate, filter membrane status, and equipment power every 2 hours.

Sampling end processing

Turn off the device: After sampling is complete, turn off the sampler and remove the sampling head.

Filter membrane preservation: Use tweezers to fold the filter membrane twice (with the dust side facing inward), place it in the filter membrane box, and label it (indicating the sampling point, time, and number).

Data recording: Record termination time, final flow rate, sampling volume, and environmental parameters.

3、 Post sampling processing

Filter membrane weighing

Constant weight treatment: Place the sampled filter membrane in a constant temperature and humidity chamber to equilibrate for 24 hours, weigh it again, and record the final mass.

Quality calculation: Dust mass=final mass - initial mass.

Concentration calculation

Calculate the dust concentration according to the formula:

The sampling volume needs to be calibrated to the standard state (25 ℃, 101.3kPa).

3. Data report

Fill in the sampling record form, including information such as the inspected unit, sampling time, flow rate, temperature and humidity, dust type, etc.

Determine whether the dust concentration exceeds the standard according to standards such as GBZ 2.1-2019.

4Dust samplerPrecautions

safety protection

Wear dust masks and goggles during sampling to avoid direct contact with high concentration dust.

Explosion proof equipment should be used in flammable and explosive places, and open flames or static electricity are prohibited.

environmental conditions

Avoid sampling in environments with rain, snow, strong winds (wind speed>5m/s), or high temperatures (>40 ℃).

Equipment maintenance

Wipe the equipment with a soft cloth after each sampling to prevent dust from entering the interior.

Regularly replace desiccants, calibrate flow meters, and send them for inspection once a year.

Fault handling

Unstable flow rate: Check if the filter membrane is clogged, if there is any leakage in the pipeline, and recalibrate the flow rate.