As the core equipment for industrial combustion efficiency testing and environmental emission monitoring, the professionalism of maintenance and repair of the Detu flue gas analyzer directly affects the accuracy of measurement data and the lifespan of the equipment. The following is an analysis of Detu flue gas maintenance, covering maintenance types, key processes, technical points, and precautions:
1、 Common maintenance types and fault manifestations
1. Sensor failure
Electrochemical sensors (O ₂, CO, NOx, SO ₂): End of life (usually 2-3 years), zero drift, slow response, data jumps.
Infrared sensor (CO ₂): Optical window contamination, light source attenuation, and excessive temperature drift.
Performance: Measurement deviation>10%, calibration cannot pass.
2. Fault in the pneumatic system
Pipeline blockage (accumulation of dust/condensate), insufficient pumping force of the air pump (aging of the pump membrane), air tightness failure (hose cracking, joint leakage).
Performance: Traffic alarm, delayed response time, and large data fluctuations.
3. Hardware damage
• Probe/probe: high temperature deformation, ceramic filter rupture, thermocouple rupture.
• Motherboard/Circuit: Power failure, abnormal display, button malfunction.
• Condensation unit: Peltier refrigeration failure, peristaltic pump blockage.
4. Software and calibration anomalies
System error, program crash, and inability to connect to the upper computer.
2、 Professional maintenance process
1. Preliminary diagnosis (user self inspection)
Air path self inspection: Check if the filter element is saturated and test for air tightness (block the probe inlet to see if the flow rate returns to zero).
Sensor calibration: Verify deviation by introducing standard gas.
Environmental testing: Check if there is an error when starting up in a low-temperature environment (possibly due to condensation water freezing).
2. Standard Process for Authorized Maintenance Centers
| Steps | Operation content |
| Disassembly and testing | Disassemble and inspect the motherboard for corrosion, air pump wear, and sensor voltage output; Infrared module light intensity test. |
| Deep cleaning | Ultrasonic cleaning of gas pipeline and replacement of peristaltic pump tube; Clean up dust in the optical cavity (operating in a dust-free environment). |
| Component replacement | Only use original sensors/air pumps. |
| Whole machine calibration | Multi concentration point standard gas calibration, in compliance with ISO7504 standard. |
| Aging test | Continuous operation for 48 hours, monitoring data stability and adaptability to high temperature conditions. |
3、 Key points of core technology
1. Sensor matching technology
Replacing the electrochemical sensor requires rewriting the EEPROM chip data, unauthorized repairs will result in the 'Sensor Invalid' error.
2. Airtightness repair standards
Use a helium mass spectrometer to detect micro leaks, and the sealing gasket must withstand temperatures greater than 200 ℃.
3. Thermocouple calibration
Multiple point calibration in the dry well furnace, with an error>± 3 ℃, needs to be replaced.
4. Deep software repair
Flashing firmware requires matching the hardware version and fixing communication protocol errors.
4、 Maintenance suggestions (key to extending lifespan)
1. Daily protection
Dustproof: Clean the probe ceramic filter element after each use (compressed air blowback).
• Anti condensation: When the flue gas temperature is below 5 ℃, enable automatic drainage, and idle for 10 minutes before stopping to drain the water vapor.
• High temperature prevention: Smoke above 800 ℃ must be accompanied by cooling sleeves.
2. Periodic maintenance
• Monthly: Replace the pre filter element and check the elasticity of the peristaltic pump tube.
Quarterly: Standard gas verification, if the deviation is greater than 5%, it needs to be returned to the factory for calibration.
Every year: Send the entire machine to the authorized center for maintenance (replacement of pipelines/seals, upgrading of firmware).
3. Lifespan of key spare parts
| Components | Replacement cycle | Failure risk |
| O ₂ sensor | 2 years | Combustion efficiency calculation error |
| Air pump diaphragm | 500 hours | Insufficient traffic leads to measurement delay |
| Peltier condensation module | 3 years | Moisture entering the sensor causes corrosion |
| Probe ceramic filter cartridge | 50 measurements | Dust blockage doubles response time |
5、 Selection criteria for maintenance services
1. Identify the authorized qualifications
Check if the maintenance organization holds a Detu authorization certificate.
2. Technical Capability Verification
Request to provide a standard gas calibration report (including multi-point error values) and repeatability test data after maintenance.
3. Accessory traceability management
Replacement of components requires the provision of original factory traceability codes.
6、 Special scenario maintenance plan
• High sulfur environment (coal-fired boilers):
Add alkaline filter to protect the sensor, and clean the gas path after sulfur corrosion.
Low temperature wet flue gas (biomass boiler):
Install electric heating pipelines to prevent condensation and increase the working temperature of the pump body to 40 ℃.
• Emergency maintenance:
Replace the plug-in sensor on site and restore basic functions within 15 minutes.
7、 Maintenance taboos
Wipe the optical module with alcohol (corrosion anti reflection film)
Non standard gas forced calibration (damaged sensor chip)
• Over range measurement