Smoke and dust concentration detector is a specialized equipment used for real-time monitoring of suspended particulate matter (such as PM2.5, PM10) concentration in the air, widely used in industrial emission monitoring, environmental law enforcement, occupational health protection and other fields. The core principles are mostly light scattering methods (such as laser scattering), beta ray absorption methods, or electrical induction methods. The following provides a detailed explanation from the aspects of operation process, parameter settings, and maintenance points.

1、 Preparation before operation

1. Equipment inspection

-Battery level and power supply: Confirm that the battery level is sufficient (usually ≥ 80%), and check the power adapter and voltage stability of the long-term power supply equipment.

-Sensor status: After turning on, observe whether the self-test is normal. For laser devices, check whether the optical path is unobstructed (without obstruction or dust accumulation).

-Calibration validity period: Check the last calibration time, if it exceeds the manufacturer's recommended cycle (such as 1 month), recalibration is required.

2. Preparation of consumables

-Backup filter membrane (to be replaced regularly for beta ray method), clean air pump (to ensure stable airflow for light scattering method).

-Anti static wiping cloth, anhydrous ethanol (used for cleaning optical lenses).

3. Environmental adaptation

-Avoid using in high temperature (>50 ℃), high humidity (>90% RH), or strong electromagnetic interference environments.

-Fixed equipment requires the installation of brackets in advance to ensure that the sampling port avoids strong winds or obstructions.

2、 Installation and Sampling

1. Sampling point selection

-Representative: Choose a location with uniform smoke diffusion (near the centerline of the smoke duct), avoiding proximity to fans or vortex zones.

-Height: During factory monitoring, the sampling port should be 1.5 to 2 meters above the ground, avoiding tree crowns or building obstructions.

-Multi point monitoring: Multiple sampling points need to be arranged in large areas to take the average value to improve data reliability.

2. Gas path connection

-Use polytetrafluoroethylene (PTFE) sampling tubes with a length not exceeding 10 meters and a bending radius greater than 0.5 meters to avoid particle deposition.

-Check the airtightness after connection: block the sampling port, the flow rate should be reset to zero, otherwise the interface needs to be resealed.

3. Preheating and stabilization

-Preheat for 10-15 minutes after turning on, and wait for the sensor to enter working temperature (such as stabilizing to 40 ℃ for laser scattering method).

-Zero calibration: Zero the instrument in a clean air environment (such as a laboratory or upwind direction).

3、 Parameter Setting and Testing

1. Core parameter adjustment

-Range selection: Choose the appropriate range based on the expected concentration (such as 0~500mg/m ³ or 0~2000 μ g/m ³).

-Sampling time: Instantaneous detection is set to 1-5 seconds, and average concentration monitoring is set to 1-15 minutes.

-Alarm threshold: In industrial safety scenarios, an over limit alarm value (such as 50mg/m ³) should be set and linked with sound and light alarms.

2. Testing process

-Continuous monitoring: continuous sampling after startup, recording real-time data and storing (supporting USB export or wireless transmission).

-Fixed point sampling: Conduct at least 3 parallel measurements according to national standards (such as HJ/T 55-2019) and take the average.

-Calibration verification: Use a standard dust generator (such as DEHS particles) to input a known concentration and verify if the instrument error is less than ± 10%.

4、 Data recording and analysis

1. Data storage

-Record environmental parameters such as time, location, temperature and humidity, and air pressure, and archive them together with concentration data.

-Some instruments support automatic report generation (such as CSV format) and require regular backup to the cloud or local hard drive.

2. Abnormal data processing

-Sudden jump values (such as sudden spikes) should be labeled with reasons (such as vehicle passing, equipment starting and stopping), and removed if necessary.

-Concentration trend analysis: Combining parameters such as wind speed and production load to determine the diffusion pattern of smoke and dust.

5、 Daily maintenance and troubleshooting

1. Cleaning and maintenance

-Optical lens: Use a dust-free cloth dipped in ethanol to gently wipe the laser emitting/receiving window every week to avoid oil or dust adhesion.

-Filter cleaning: Disassemble the sampling port filter every month, rinse it with clean water and air dry it to prevent blockage.

-Internal dust removal: Use a soft bristled brush to clean the gaps in the chassis to avoid dust accumulation that affects heat dissipation.

2. Calibration and Calibration

-Zero calibration: Zero in clean air, with an error of<± 2% FS.

-Span calibration: Introduce standard concentration gas (such as 200mg/m ³) and adjust it to the theoretical value with an error of<± 5% FS.

-Periodic calibration: sent to a third-party organization (such as a metrology institute) for verification every six months to ensure compliance with metrology standards.

3. Common troubleshooting

-Low value: Check for air path leaks, clogged filter membranes, or aging sensors.

-Zero drift: recalibrate or check for contamination inside the optical cavity.

-Communication interruption: Restart the module or check the antenna/SIM card (wireless type).

6、 Safety and Standards

1. Protective measures

-Wear dust masks and anti-static gloves during on-site operations to avoid direct contact with high concentrations of smoke and dust.

-Outdoor work is prohibited during thunderstorms to prevent equipment leakage.

2. Compliance requirements

-Regularly submit monitoring reports in accordance with national standards (such as GB 16297-1996) and local environmental regulations.

-The scenario needs to be accompanied by log recording (such as device running time, maintenance records).

7、 Special scenario applications

1. High temperature/high humidity environment

-Install heat tracing tubes (maintain sampling tube temperature>120 ℃) to prevent interference from water vapor condensation.

-Choose waterproof casing (IP65 or above) and regularly apply moisture-proof agent.

2. Explosion proof area

-Choose Exd IICT6 explosion-proof certification equipment and prohibit battery replacement or maintenance in hazardous areas.