Honeywell 05701-A-0405

3. Technical Specifications

• Official Part Number: 05701-A-0405
• Detected Target Gas: Carbon Monoxide (CO)
• Standard Measuring Range: 0 ~ 500 ppm CO
• Nominal Output Signal Span: Linear millivolt output, full-scale output value 45 ±5 mV @500 ppm CO standard calibration gas
• Zero Offset Voltage: ≤±1.2 mV under clean fresh air ambient condition at 25℃
• Rated Operating Supply Voltage: No external driving voltage required; passive electrochemical working mode powered by redox chemical reaction inside electrolyte
• Response Time T90: ≤35 seconds when exposed from clean air to full-scale 500 ppm calibrated CO gas
• Recovery Time T10: ≤55 seconds when switching from full concentration gas back to fresh clean ambient air
• Operating Ambient Temperature Range: -20 ℃ ~ +50 ℃; certified storage temperature: -30 ℃ ~ +60 ℃
• Applicable Working Relative Humidity: 10% ~ 95% non-condensing ambient humidity
• Maximum Allowable Ambient Barometric Pressure: 80 kPa ~ 120 kPa
• Physical Overall Dimension: Diameter 32.5 mm, total height 18.2 mm; single unit net weight 14.8 g
• Intrinsic Safety Grade: Ex ia IIC T6 for hazardous explosive zone installation

4. Functional Characteristics

1. Electrochemical three-electrode structural design completes continuous redox reaction when target CO gas penetrates internal gas permeable membrane, converting gas concentration variation into proportional linear millivolt electrical output signal.
2. Built-in anti-poisoning composite filtering layer blocks organic solvent vapor, sulfur-containing gas and acidic gas molecule infiltration to avoid irreversible electrode poisoning failure of internal sensitive electrode core.
3. Integrated internal electrolyte storage cavity with long-life sealed structure, fixed electrolyte capacity matching design service cycle without on-site liquid replenishment operation.
4. Standard three-lead terminal definition: Working Electrode, Counter Electrode, Reference Electrode, direct pin-to-socket docking with matched Honeywell host detector PCB without intermediate signal conversion circuit.
5. Internal temperature compensation electrode layout suppresses output drift caused by ambient temperature fluctuation to maintain consistent linear output characteristic within full rated working temperature interval.
6. Fixed linear proportional output characteristic conforms to Beer-Lambert concentration response rule, supporting host controller direct concentration calculation via fixed conversion coefficient without nonlinear secondary correction programming.
7. Compatible with full Honeywell fixed gas detector series host circuit board, supports field single module plug-and-play replacement after periodic service cycle expiration.

5. Performance Parameters

• Full-scale linearity error: ≤±2%FS within entire 0~500ppm measurement range under rated ambient condition
• Long-term zero drift per month: ≤0.8 mV/month under continuous fresh air storage environment
• Cross-interference error: ≤±1.5%FS when exposed to 100ppm H₂S, 200ppm NO, 500ppm ethanol vapor interfering gas separately
• Vibration resistance standard: Pass 10Hz~150Hz continuous vibration test at 5g acceleration without internal electrolyte leakage and output characteristic deviation
• Service life under rated working environment: Fixed certified design life 24 calendar months from factory production date
• EMC anti-interference index: No output signal jump deviation under 10V/m RF radiation electromagnetic field environment
• Over-range tolerance: Short-term continuous exposure under 800ppm high-concentration CO does not cause permanent irreversible electrode damage, automatically recovers standard output after returning to clean air

6. Material Composition

1. Outer Protective Shell: High-density PP polypropylene injection molding housing with chemical corrosion resistant modification treatment, UL94-V2 flame retardant grade
2. Gas Inlet Outer Filter Membrane: PTFE polytetrafluoroethylene microporous breathable film with fixed 0.2μm pore size to block solid dust particle infiltration
3. Internal Anti-poison Filter Layer: Activated carbon + molecular sieve composite adsorption filter core packaged inside PP fixed support frame
4. Three Core Electrode Material: Working & Counter electrode adopts high-purity platinum-plated porous carbon substrate; reference electrode is silver/silver chloride (Ag/AgCl) solid-state electrode
5. Internal Electrolyte Liquid: Buffered acidic water-based inorganic electrolyte sealed inside epoxy isolated cavity, non-volatile modified formulation
6. Bottom Terminal Lead Pin: Oxygen-free copper base with nickel pre-plating + surface gold plating ≥0.3μm thickness for anti-oxidation and stable contact conduction
7. Internal Sealing Component: EPDM ethylene propylene rubber O-ring for full cavity liquid tight sealing to prevent electrolyte volatilization leakage

7. Structural Features

1. Concentric layered cylindrical modular structure arranged sequentially from outside to inside: outer protective casing, dustproof breathable membrane, composite anti-poison filter layer, three-electrode reaction cavity, bottom fixed terminal assembly.
2. Top central single circular gas inlet opening as exclusive gas diffusion channel, surrounding closed solid plastic structure to prevent side air bypass diffusion affecting measurement precision.
3. Internal electrode fixed by insulating PET plastic positioning spacer, fixed gap layout between each electrode to avoid short-circuit contact caused by electrode deformation.
4. Bottom three independent vertically protruding metal pins with fixed spacing dimension matching Honeywell standard detector PCB socket foot position, no position modification required during plug-in installation.
5. Fully closed isolated electrolyte storage cavity separated from gas diffusion channel by ion exchange membrane to realize gas pass-through and liquid block dual physical isolation effect.
6. External reserved annular positioning groove for matching detector housing fixed buckle clamping positioning during equipment assembly.

8. Working Principle

9. Advantage Highlights

1. Original Honeywell factory calibrated finished sensing component with complete production batch traceability and official calibration report, direct plug-in replacement for matched Honeywell fixed gas detector without on-site secondary gas calibration after regular replacement.
2. Composite multi-stage anti-poison filtering structural design effectively isolates common industrial interfering gas, greatly reducing cross-sensitivity error for complex on-site factory atmosphere environment.
3. Built-in passive electrochemical working structure eliminates extra auxiliary excitation power consumption circuit on host controller side, simplifying overall detector circuit design and reducing equipment failure points.
4. Wide rated temperature and humidity working range adapts outdoor open-air installation and high-humidity factory workshop harsh working environment without additional constant-temperature protection housing.
5. Standard unified three-pin mechanical dimension realizes interchangeable spare part management across all matched Honeywell host equipment models, reducing spare part inventory stocking variety and management cost.
6. Global ATEX, SIL2, CE full safety certification supports gas detection equipment export deployment across European, Asian and American industrial sites without supplementary safety certification.

10. Applicable Industries

• Petrochemical Production Industry: Refinery workshop, chemical reactor auxiliary room CO leakage continuous monitoring
• Metallurgy Steelmaking Industry: Blast furnace auxiliary workshop, heat treatment furnace flue gas CO concentration detection
• Underground Municipal Engineering Industry: Underground pipe gallery, municipal sewage pump room toxic gas safety monitoring
• Automobile Manufacturing Industry: Vehicle painting workshop, engine test bench CO leakage alarm control
• Commercial Building & Underground Parking Industry: Closed underground parking lot real-time CO safety monitoring and ventilation linkage control
• Mining & Tunnel Construction Industry: Construction tunnel auxiliary operation area toxic carbon monoxide early warning detection

11. Applicable Model Series

• Peer Same Product Lineup: Honeywell 05701 series multi-gas specification sensors including 05701-A-0305(H₂S),05701-A-0205(NO),05701-A-0505(SO₂)
• Matching Host Detector Series: Honeywell SPXLT, XCD, U2 fixed industrial gas transmitters and wall-mounted CO alarm controllers
• Supporting Auxiliary Parts: Honeywell standard detector plastic housing, replacement filter membrane accessories and host PCB main control boards

12. Installation Requirements

1. Complete module plug-in installation operation under full power-off state of matched gas detection host equipment, align three bottom metal pins vertically with host PCB corresponding socket hole and insert straightly without forced skew extrusion.
2. Confirm top gas inlet opening keeps unobstructed upward orientation after installation, reserve minimum 20mm free space above gas inlet to avoid pipeline, wiring or component blocking gas diffusion channel.
3. Install host detector at height 1.2~1.5m above ground level for CO gas monitoring per industrial installation specification, avoid direct mounting near high-temperature heat source and air blower direct airflow impact position.
4. After module installation completion, execute standard calibration with certified 250ppm CO span calibration gas before formal system commissioning to verify full-scale output value conforms factory specification range.
5. Keep surrounding installation environment free of strong corrosive liquid splash and organic solvent volatilization during commissioning stage, complete host zero point adjustment under clean fresh air ambient condition.
6. Separate detector power wiring from high-voltage AC power cable with minimum 10cm wiring spacing to avoid power frequency electromagnetic interference causing unstable sensor output drift.

13. Usage Precautions

1. Strictly prohibit manual disassembly of outer shell and internal layered filter structure; arbitrary shell opening causes internal electrolyte volatilization and irreversible electrode failure leading to permanent module scrap.
2. Prevent corrosive chemical liquid, engine oil, paint thinner solvent from direct splashing onto top gas inlet breathable membrane; cut off host power supply immediately once liquid contamination occurs and replace sensor with new certified spare part directly.
3. Forbid long-term continuous sealed storage of unused spare modules inside airtight non-ventilated plastic bag; spare parts must be stored in original factory breathable packaging bag under specified constant temperature dry warehouse environment.
4. Execute fixed periodic maintenance inspection every 90 working days: check gas inlet membrane dust clogging condition, host zero drift value and span output accuracy, record all measured data into equipment maintenance archive log; replace entire sensor module upon reaching 24-month certified design service life.
5. Store spare unused sensor inside original factory sealed packaging under 15℃~25℃ constant dry indoor environment, forbid long-term outdoor storage under direct sunlight, high-temperature damp or freezing low-temperature ambient condition.
6. Avoid long-term continuous exposure of installed sensor to high-concentration organic solvent vapor environment; sustained high-concentration interfering gas infiltration will accelerate internal electrode poisoning and shorten rated service life cycle.