CITY MICROPEL 75 75C PM759-000 PM769-000 Combustible gas sensor

CITY MICROPEL 75 75C PM759-000 PM769-000 Combustible gas sensor Parameters Brand: City Model: 75 75C Principle: Catalytic oxidation (Pellistor), used to detect the lower limit of combustible gas explosion (LEL). Origin: UK 1. Testing performance Range: 0~100% LEL (Methane 0~5% VOL) Target gases: light combustible hydrocarbons such as methane, ethane, propane, butane, hydrogen, and CO Not suitable for: high carbon hydrocarbons, alcohols, ketones, esters, high concentrations of H₂S Sensitivity: 31±5 mV/% methane T90 Response Time: <5s (Methane) Linear interval: 0~3% methane with excellent linearity Resolution: 1% LEL Anti-poisoning: Enhanced anti-silicone and hydrogen sulfide resistance; The filter has a total capacity of 1000 ppm·hr H₂S Filter lifespan: Normal operating conditions> 5 years 2. Electrical parameters Rated power supply: 3.30 VDC ±0.02V Operating current: 78±6 mA Maximum power consumption: 295 mW Structure: Dual beads (Detector beads, Compensator beads), 3-pin output 3. Environment and Machinery Operating temperature: -20°C ~ 55°C Temperature and humidity: 0~90% RH, non-condensing Pressure: Standard atmospheric pressure ±20% Weight: 2g Installation: Azimuth sensitivity, usable at any angle Housing: 316 stainless steel, IP6X protection 4. Lifespan and drift Expected service life: 5 years in air Long-term range drift: <5% signal per month Zero drift: <5% LEL methane per month 3. Core differences between the 75 and 75C 75C adds a dedicated H₂S filter layer, greatly improving the environmental lifespan of sulfides and silicones; The 75 Standard Edition lacks a reinforced filter layer, making it prone to poisoning and failure 75C fully certified ATEX/UL explosion-proof components, suitable for industrial explosion-proof equipment; 75 Basic model certification simplified 75C is the universal standard for portable four-in-one/two-in-one gas detectors (BW, Honeywell instruments). 4. Typical Application Scenarios Portable Composite Gas Detector (LEL Combustible Channel) Natural gas and gas pipeline leak inspection instruments LEL monitoring in underground utility tunnels, ship holds, gas stations, and chemical workshops Safety inspection for confined space operations 5. Precautions for Use A 3.3V constant voltage driver circuit must be used; direct 5V power supply is not allowed, as it will burn out the catalytic beads Silicone gel, silicone oil, and high concentrations of H₂S can permanently poison catalytic beads, so avoid them on site Long-term high-temperature/high-humidity condensation accelerates zero drift; it is recommended to calibrate every 3~6 months The sensor must not be disassembled, and the internal lead acetate filter layer may be damaged, posing contact hazards Sensitivity slightly decreases in low-temperature environments below 0°C; software compensation is required for low-temperature use 6. Pin Definition (3Pin) DETECTOR: Detection beads COMPENSATOR: Compensation beads V: 3.3V power supply positive terminal …