ODM Smart Sensor Combustible Gas Detector Supplier

The Lower Explosive Limit (LEL) represents the minimum concentration of a combustible gas or vapor in air required to support combustion or cause an explosion when an ignition source is present (for Methane CH4, 100% LEL corresponds to 5.0% Volume concentration in air).

Alarm Set Points are safety thresholds configured inside the gas detector instrument well below the actual explosive limit. Standard safety protocols set Low Alarm (A1) at 20% LEL to 25% LEL (which equals 1.0% CH4 by Volume) and High Alarm (A2) at 50% LEL. This guarantees ample response time for personnel evacuation and automatic shut-off valve actuation long before dangerous gas levels are reached.

Normal atmospheric air contains approximately 20.9% Oxygen (O2) by Volume (%VOL). Toxic gases (such as H2S or CO) are monitored at trace levels using parts per million (ppm) because exposure to even 10 ppm of H2S is hazardous.

Because Oxygen is a major component of air, monitoring oxygen enrichment (>23.5% VOL) or oxygen deficiency (<19.5% VOL) in confined spaces or welding pipe chambers requires high-range resolution expressed in percent volume (%VOL). 1% VOL equals 10,000 ppm; thus, a ppm scale would yield unnecessarily cumbersome numerical values (e.g., 209,000 ppm).

When a Shield Smart Sensor Combustible Gas Detector (such as the SD6103K or SD2100E) detects gas exceeding the pre-set alarm value, its internal microprocessor triggers an acoustic/visual warning and simultaneously closes a high-current relay contact or discharges a capacitive pulse output (typically DC 9V-12V pulse).

This pulse energizes the coil of an electromagnetic valve (such as the JYFJS-011 Series), triggering a instantaneous mechanical release that snaps the valve disc shut in under 1 second. Shield shut-off valves utilize a manual pull-up reset mechanism: even if the gas dissipates and the detector stops alarming, the valve remains locked shut until maintenance personnel inspect the leak point and physically pull the reset knob, preventing dangerous automated gas supply resumption.

Yes. As an experienced ODM manufacturer, Sichuan Shield Technology offers customized firmware development. We routinely integrate customized register maps for RS-485 Modbus RTU, M-Bus protocols, and wireless IoT connectivity (LoRaWAN, NB-IoT, MQTT over cellular).

We can align telemetry data packet structures to transmit sensor state, battery level, temperature compensation metrics, calibration dates, and self-diagnostic fault codes directly to your proprietary municipal cloud management platform.

Combustible gas sensors can experience cross-sensitivity when exposed to volatile organic compounds (VOCs) such as alcohol vapors, cooking vapors, or cleaning solvents. Shield addresses this through dual-stage engineering:

• Hardware Level: Incorporating activated carbon physical filter layers and physical diffusion membranes inside sensor chambers to absorb heavy silicones and ambient alcohol vapors.
• Algorithmic Level: Employing intelligent multi-channel signal differentiation that analyzes peak gas absorption slopes, reducing false alarms triggered by momentary household cleaning spray releases.

For standard OEM customization (including custom brand logo printing, customized product labels, modified user manuals, and customized box artwork), our Minimum Order Quantity (MOQ) typically starts at 500 units, with production lead times of 14 to 21 business days post sample approval.

For full ODM projects requiring custom housing molds or new PCB hardware engineering, prototype samples are delivered within 4 to 6 weeks, followed by pilot production upon verification.