CITY MICROPEL 75 75C PM759-000 PM769-000 Combustible Gas Sensor

CITY MICROPEL 75 75C PM759-000 PM769-000 Combustible Gas Sensor Specifications Brand: City Model: 75, 75C Principle: Catalytic oxidation (Pellistor), used to detect the lower explosive limit (LEL) of combustible gases Origin: UK 1. Detection Performance Range: 0~100% LEL (Methane 0~5% VOL) Target gases: Methane, ethane, propane, butane, hydrogen, CO, and other light combustible hydrocarbons Not suitable: Heavy hydrocarbons, alcohols, ketones, esters, high-concentration H₂S Sensitivity: 31±5 mV / % methane T90 response time: <5s (methane) Linear range: Excellent linearity within 0~3% methane Resolution: 1% LEL Poison resistance: Enhanced resistance to silicone and hydrogen sulfide; filter total capacity 1000 ppm·hr H₂S Filter lifespan: >5 years under normal conditions 2. Electrical Parameters Rated supply: 3.30 VDC ±0.02V Operating current: 78±6 mA Max power consumption: 295 mW Structure: Dual bead (Detector & Compensator), 3-pin output 3. Environmental & Mechanical Operating temperature: -20℃ ~ 55℃ Humidity: 0~90% RH, non-condensing Pressure: Standard atmospheric ±20% Weight: 2g Mounting: No directional sensitivity, can be used at any angle Housing: 316 stainless steel, IP6X protection 4. Lifespan & Drift Expected lifespan: 5 years in air Long-term span drift: <5% signal/month Zero drift: <5% LEL methane/month Key Differences Between 75 and 75C 75C adds a dedicated H₂S filter layer, greatly improving lifespan in sulfurous and silicone environments; standard 75 has no enhanced filter, easy to get poisoned 75C has full ATEX/UL explosion-proof certification, suitable for industrial explosion-proof equipment; 75 has simplified certification 75C is the standard for portable four-in-one/two-in-one gas detectors (BW, Honeywell) Typical Applications Portable multi-gas detectors (LEL combustible channel) Natural gas and pipeline leak inspection instruments LEL monitoring in underground pipelines, ship cabins, gas stations, chemical workshops Confined space safety checks Usage Notes Must be paired with a 3.3V constant voltage driver circuit; do not directly supply 5V, which will destroy the catalytic bead Silicone glue, silicone oil, and high-concentration H₂S can permanently poison the catalytic bead; avoid on-site exposure Long-term high temperature/high humidity condensation accelerates zero drift; calibration recommended every 3~6 months Sensor cannot be disassembled, internal lead acetate filter layer poses contact hazard if damaged Sensitivity slightly decreases below 0℃; low-temperature use requires software compensation Pin Definition (3Pin) DETECTOR: Detector bead COMPENSATOR: Compensator bead V: 3.3V supply positive