1、 Instrument positioning and core functions
The sulfur dioxide detector is a specialized equipment used to monitor the concentration of sulfur dioxide (SO ₂) in the environment. Its core value lies in ensuring industrial safety, environmental compliance, and human health through real-time detection and warning. As a colorless and pungent toxic gas, sulfur dioxide is widely present in power, chemical, metallurgical, agricultural, and enclosed workplaces (such as coal mines and non coal mines). Long term exposure may cause respiratory diseases, acid rain, and other environmental problems. The detector converts gas concentration into readable data through principles such as electrochemical sensors, infrared technology, or spectral analysis, and supports functions such as concentration display, over limit alarm, and data transmission.
2、 Instrument type and applicable scenarios
According to the structure and application requirements, sulfur dioxide detectors can be divided into the following types:
Fixed detector
Scenario: Long term deployment in fixed locations such as factories and mines, achieving 24-hour continuous monitoring.
Features: Supports 4-20mA current signal RS485、 Frequency and other standard signal outputs can be connected to industrial control systems (such as DCS, PLC) to achieve automated linkage control. For example, in chemical production, when the concentration of SO ₂ exceeds the threshold, the system automatically activates the exhaust device and triggers an alarm.
Handheld/portable detector
Scenario: Suitable for temporary inspection, patrol or mobile operations, such as on-site law enforcement by environmental protection departments and gas monitoring in agricultural greenhouses.
Features: Built in air pump (pump suction) or relies on natural diffusion sampling, equipped with LCD/OLED display screen, real-time display of concentration values. Some models support Bluetooth/data cable data export for subsequent analysis. For example, underground coal mine workers can wear safety helmets with portable detectors to monitor the accumulation of SO ₂ in the lower part of the tunnel in real time.
Online analyzer and alarm
Scenario: Integrated into environmental monitoring stations, pollution source discharge outlets, etc., to achieve high-precision and long-term stable monitoring.
Features: Adopting modular design such as infrared heating, nitrogen blowing control, magnetic stirring, etc., supporting segmented heating, automatic acid addition, automatic cleaning and other functions, meeting the precise determination of SO ₂ residue in food and medicine. For example, in the testing of traditional Chinese medicine, the content of SO ₂ is analyzed by distillation titration method to ensure compliance with the standards of the Chinese Pharmacopoeia.
Explosion proof detector
Scenario: Designed specifically for flammable and explosive environments such as coal mines and petrochemicals, in compliance with the Coal Mine Safety Regulations and the Metal Non Metal Underground Mining Safety Regulations.
Features: The shell is made of shockproof, waterproof, and radio frequency interference resistant materials, which can withstand a drop of 1.8 meters; Equipped with a built-in 1500mAh lithium battery, it can last for up to 2 years; When exceeding the standard, trigger a 95dB buzzer and red green LED alarm to ensure the safe evacuation of workers.
3、 Full process usage details and precautions
Preparation before use
Equipment inspection: Confirm that the host, sensors, sampling probes, batteries, and other accessories are complete. The lifespan of electrochemical sensors is usually 1-2 years, and it is necessary to check whether they are within their validity period.
Calibration operation:
Zero point calibration: performed in clean air to eliminate environmental interference.
Calibration of standard gas: Use a known concentration of standard gas (such as 10ppm SO ₂ standard gas) to adjust the instrument reading to the accurate value. Some models support one click calibration function, simplifying the operation process.
Preheating and self-test: Wait for 10 seconds to a few minutes after turning on the device to complete the self-test. Some instruments need to be preheated to a stable state (such as electrochemical sensors that require a response time of 30 seconds).
Detection operation
Sampling method:
Diffusion type: Place the instrument in the gas to be measured, wait for natural diffusion and read, suitable for open spaces.
Pump suction: Connect the sampling tube, start the suction pump to suck in gas, suitable for closed or remote sampling.
Data recording: Save the record after the value stabilizes, and support unit free switching (such as ppm, mg/m ³,% Vol, etc.).
Alarm handling: If the concentration exceeds the preset threshold, the instrument triggers an audible and visual alarm, and the scene must be immediately evacuated and the leakage source investigated.
Post use maintenance
Cleaning and Storage: Wipe the surface of the instrument with a soft cloth and avoid using corrosive liquids; Store in a dry, non corrosive gas, and suitable temperature and humidity environment.
Regular calibration: Calibrate every 1-3 months based on usage frequency to ensure data accuracy.
Consumables replacement: Regularly replace vulnerable parts such as filters and sensors to extend the lifespan of the instrument.
safety protection
Personnel protection: Wear gas masks, rubber gloves, and goggles during testing to avoid direct contact with SO ₂ gas.
Emergency response: If the instrument reading is abnormal or the alarm fails, immediately suspend the detection and contact the manufacturer for maintenance; When high concentration SO ₂ leaks, quickly activate the emergency plan, evacuate personnel, and lock the scene.
4、 Technical parameters and selection suggestions
Detection range: 0-1000ppm (universal type), some models can be extended to 0-5000ppm (high concentration scenario).
Accuracy: ± 3% F.S (fixed) to ± 5% F.S (portable), meeting national standard requirements.
Response time: ≤ 30 seconds (electrochemical sensor), some models shorten it to 10 seconds.
Working environment: Temperature range of -40 ℃ to 60 ℃, humidity ≤ 95% RH, suitable for harsh conditions.
Selection suggestion:
Long term monitoring with fixed type and temporary testing of player's holding type;
Choose explosion-proof type for flammable and explosive environments, and online analyzer for food and drug testing;
Prioritize selecting models that support multi probe expansion, wireless transmission, and compatibility with industrial control systems to improve management efficiency.