I. Scientific Selection: Ensuring Measurement Reliability from the Source
Accuracy begins with correct selection; it is essential to ensure a high degree of matching between the sensor and the usage scenario.
1. Matching Explosion-Proof Rating
Intrinsically safe sensors with a mining product safety mark (MA) and explosion-proof certificate must be used in coal mines. Explosion-proof markings such as "Ex ib I" should be clearly legible.
2. Adapting to the Detected Object and Environment
Avoid using catalytic combustion sensors in environments containing silicon or sulfur compounds to prevent "poisoning" failure.
For high humidity or corrosive gas environments, products with stainless steel housings and IP68 protection ratings should be selected to improve sealing.
3. Allowing for Range Margin
Select sensors with a range at least 20% higher than the actual operating conditions to avoid long-term overload leading to changes in the elastomer structure or weld breakage.
II. Enhancing Environmental Adaptability: Reducing External Interference Factors
Complex operating conditions are a major cause of sensor drift and failure; targeted protective measures are necessary.
1. Temperature Control: High temperatures accelerate component aging and cause coating materials to melt. In high-temperature environments (>60℃), heat shields or water/air cooling devices should be installed.
2. Moisture and Dust Protection: Moisture and dust can easily cause short circuits. Sensors with welded seals or vacuum-filled nitrogen structures should be selected, as their sealing performance is superior to rubber gaskets or adhesive seals.
3. Electromagnetic Interference Resistance: Strong electromagnetic fields can cause output signal turbulence. Shielded cables should be used and reliably grounded; filters should be installed if necessary.
4. Corrosion Prevention: In acidic, alkaline, or salt spray environments, sensors with powder-coated finishes or 304 stainless steel housings should be selected, and surface corrosion should be checked regularly.
III. Standardized Calibration and Verification: Ensuring Continuous Data Accuracy
Regular calibration is the core means of maintaining accuracy and must be implemented in conjunction with a dynamic triggering mechanism.
1. Set Calibration Cycles by Type
Methane Sensor (Catalytic): Monthly
Carbon Monoxide Sensor: Quarterly
Temperature/Pressure Sensor: Semi-annually
Speed/Position Sensor: Annually
(Under special operating conditions, the cycle should be shortened by 30%-50%)
2. Standardize Calibration Procedures
Before calibration, confirm environmental compliance (temperature 15-25℃, no strong interference). Use a traceable standard gas or signal source to complete zero-point, accuracy, and alarm point calibration, and write the parameters to memory.
3. Post-Calibration Verification is Mandatory
Confirm sensor performance meets standards through steady-state testing, repeatability verification, response time testing, and alarm function testing.
IV. Systematic Management: Building a Long-Term Protection Mechanism
Integrate sensors into the overall safety management system to improve reliability.
1. Use with Safety Barriers
Intrinsically safe systems must be used with safety barriers to limit loop energy and prevent overvoltage and overcurrent damage to the sensor.
2. Set Early Warning Mechanisms
Configure abnormal data alarms (such as drift exceeding limits, slow response) in the monitoring system to achieve early intervention.
3. Establish Maintenance Records: Record the time of each cleaning, calibration, and replacement to facilitate tracking performance change trends and enabling predictive replacement.
4. Personnel Training and Operating Procedures: Operators should master basic judgment methods and promptly report and handle any abnormal readings or alarm malfunctions.
