A fixed gas detector continuously monitors the air in a plant area for oxygen deficiency, toxic gas leaks or combustible gas concentration, triggering an alarm before conditions become dangerous. IJ Instruments supplies flameproof, PESO certified smart gas detectors covering Oxygen, Toxic, Combustible and VOC gases — with hot-swappable sensor modules for fast, low-downtime maintenance.
Understanding Gas Detection
A fixed gas detector uses a sensor module to continuously sample the surrounding air and measure the concentration of a specific gas. When the reading crosses a pre-set alarm level, the detector triggers a relay output, sound/light alarm and a proportional 4–20mA or digital signal to your control system — giving personnel and automated safety systems time to respond before a leak becomes hazardous.
Best for accurate, low-level detection of most toxic gases (CO, H₂S, Cl₂, NH₃) — the sensor generates a current proportional to gas concentration through a chemical reaction.
Used for combustible gas detection (%LEL) — a heated catalytic bead's resistance changes as combustible gas burns on its surface.
Non-Dispersive Infrared sensors measure gases like CO₂ and hydrocarbons by their infrared absorption — immune to sensor poisoning, long service life.
Photoionization Detectors for Volatile Organic Compounds (VOCs) and low-level hydrocarbons, ionizing gas molecules with UV light to generate a measurable current.
Electrochemical cells specifically calibrated to measure oxygen concentration — critical for confined space entry and inert-atmosphere monitoring.
Metal-oxide semiconductor sensors for combustible and some toxic gases, valued for ruggedness and long operating life.
Gas Coverage
The right sensor module is selected based on your target gas and required range. Below is the coverage available across our gas detector range.
Don't see your specific gas listed? Share your requirement — additional gases can often be covered with the appropriate sensor module.
Featured Product
One flameproof, PESO certified platform covers Oxygen, Toxic, Combustible and VOC gas detection with a hot-swappable sensor module design.
A flameproof, PESO certified smart gas detector with an 8×2 alphanumeric LCD display and 8 status LEDs, designed for swift, reliable detection of Oxygen, Toxic, Combustible and VOC gas leaks. The hot-swappable gas sensor module stores its own calibration, alarm, offset and output-current data — so replacing a sensor doesn't mean reprogramming the whole unit.
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Why IJ Instruments
Share your target gas, hazardous area classification and mounting environment — we'll help you specify the right sensor module and output configuration.
As a dealer and supplier for gas detection equipment in India, we help you source PESO certified detectors with local technical support.
Datasheets, certification documents and calibration guidance to support your engineering and procurement process.
Coordinated sourcing and delivery to plants, EPC contractors and system integrators across India.
FAQs
A flameproof (Ex d) enclosure is built to contain an internal explosion so it cannot ignite the surrounding atmosphere, while an intrinsically safe (Ex ia) design limits electrical energy in the circuit so it can never generate a spark capable of ignition — both approaches are used depending on the hazardous area classification and installation requirement.
Calibration is generally recommended annually, though this depends on usage and environmental conditions such as exposure to gas events or contaminants. A hot-swappable sensor module design lets you replace a due-for-service sensor with a pre-calibrated one with minimal downtime.
The detector electronics and display are common across gas types, but each specific gas requires its own sensor module matched to that gas and range — the platform's modular design lets you standardize on one detector housing across different applications.
IJ Instruments is a dealer and supplier for gas detection equipment in India, supporting product selection, technical consultation and sourcing.
Share your target gas and hazardous area requirement for a free technical consultation.