Honeywell SR-W-MP75C MICROpeL Combustible LEL Sensor

Overview

The Honeywell SR-W-MP75C is a genuine replacement MICROpeL combustible (LEL) gas sensor engineered for the BW Technologies by Honeywell portable gas detection platform, including the GasAlertMicroClip XT, XL and X3, GasAlertMax XT II, and GasAlertMicroClip families. Built around Honeywell’s MICROpeL catalytic bead sensing element, the SR-W-MP75C measures flammable gas and vapor concentration across a 0 to 100% Lower Explosive Limit (LEL) range with 1% LEL resolution, giving safety officers and gas testing technicians a dependable, factory-calibrated replacement part that restores full combustible-gas detection performance without replacing the entire instrument.

Working closely with plant engineers in the region, Seven Star LLC proudly supplies the SR-W-MP75C to refineries, LNG terminals, downstream processing plants, and HSE departments across the Sultanate of Oman and the wider GCC. Facilities in Muscat, Sohar, and Salalah can source Honeywell replacement sensors for confined-space entry teams, hot-work crews, and permit-to-work programs through Seven Star LLC, with manufacturer documentation and technical support.

Measurement Principle

The Honeywell SR-W-MP75C uses a catalytic (pellistor) bead sensing technology in which a heated, catalyst-coated bead oxidizes combustible gas molecules that diffuse through the sensor’s filter and flame arrester. The oxidation reaction raises the bead’s temperature and, consequently, its electrical resistance, in direct proportion to the concentration of flammable gas present in the surrounding atmosphere. This resistance change is measured against a reference (compensator) bead in a balanced Wheatstone-bridge circuit, producing a clean, linear millivolt output that the host instrument’s microprocessor converts into a percentage of the Lower Explosive Limit.

Because the MICROpeL sensing element is designed for enhanced resistance to H2S and silicone poisoning, it maintains stable sensitivity over repeated calibration cycles in demanding oilfield, petrochemical, and marine environments. The practical result for the end user is a sensor that requires no field electronics adjustment beyond routine bump testing and calibration, drops directly into the existing sensor cradle, and restores full four-gas or single-gas monitoring capability within minutes, minimizing instrument downtime during safety-critical operations.

Engineering Design of the Honeywell SR-W-MP75C

Physically, the Honeywell SR-W-MP75C is housed in a compact cylindrical sensor cartridge with gold-plated pin contacts that mate directly with the sensor socket inside compatible BW Technologies instruments, requiring no soldering, wiring, or recalibration hardware beyond the instrument’s standard auto-calibration routine. The sensing element is protected by a filter and flame arrester while still allowing rapid gas diffusion; Honeywell specifies a T90 response time of under 5 seconds for methane on the MICROpeL 75C element.

The cartridge is rated for operation across a wide ambient temperature range of -20°C to +55°C, which covers typical Gulf summer heat. Its plug-and-play mechanical interface means field technicians can replace an expired or damaged sensor in under a minute using only the instrument’s sensor door, with no special tools required, and the sensor is fully compatible with automated docking-station calibration systems such as the Honeywell Micro Dock II and IntelliDoX platforms for streamlined fleet management.

Key Features

The Honeywell SR-W-MP75C replacement LEL sensor delivers dependable combustible gas detection with the following key characteristics:

• Genuine Honeywell MICROpeL catalytic bead sensing element calibrated at the factory for 0-100% LEL methane or pentane equivalence.
• Direct plug-and-play compatibility with GasAlertMicroClip XT, XL, X3, GasAlertMax XT II, and related BW Technologies instruments.
• Enhanced H2S and silicone poison resistance, with a typical filter lifetime of more than 5 years.
• Operating temperature range of -20°C to +55°C.
• Fast T90 response time supporting rapid confined-space entry and hot-work permit gas testing.
• Full compatibility with automated calibration docking stations for streamlined fleet-wide maintenance.
• Long service life with stable zero and span calibration across repeated bump tests.
• Simple field replacement without soldering, rewiring, or specialist tools, minimizing instrument downtime.

Industrial Applications

The Honeywell SR-W-MP75C is a critical spare part for any facility running a portable gas detection safety program, including oil and gas upstream production, refining and petrochemical processing, LNG loading and storage terminals, marine bunkering operations, and confined-space entry teams working in tank farms, sewer systems, and process vessels. HSE managers rely on genuine replacement sensors like the SR-W-MP75C to keep instrument fleets compliant with permit-to-work and confined-space entry regulations without the calibration drift risk associated with counterfeit or expired third-party sensors.

With fast quotation turnaround and technical support, Seven Star LLC distributes the SR-W-MP75C throughout Oman and the GCC, supporting refineries and industrial zones in Sohar, Salalah, and Muscat as well as offshore platforms and district cooling plants that depend on continuous combustible gas monitoring. Safety departments can request a quotation to replace expired or damaged sensors, with availability and lead time confirmed at quotation.

Technical Specifications

The table below summarizes the primary technical specifications of the Honeywell SR-W-MP75C replacement combustible sensor, confirming why the Honeywell SR-W-MP75C remains the trusted choice for regional gas detection fleets.

Gas Response and Relative Sensitivity

The MICROpeL 75C catalytic element is specified by Honeywell for methane, ethane, propane, butane, pentane, hexane, carbon monoxide and hydrogen, with linear response up to 3% methane and a sensitivity of 31 ±5 mV per % methane. Relative response, with methane taken as 100, is 56 for propane, 58 for n-butane, 72 for n-pentane, 144 for hydrogen, 96 for ethylene, 99 for acetylene and 61 for n-heptane.

Honeywell states that these relative response figures were derived experimentally at the same percentage of LEL, using 2.5% volume methane as the reference. They are given for guidance only and do not form part of the specification, so the instrument should be calibrated with the gas under investigation to obtain the most accurate readings.

Poisoning and Inhibition of Catalytic Sensors

Catalytic sensors can be affected by certain compounds. Poisoning is cumulative and irreversible: lead or sulphur compounds, silicones and phosphates form a barrier over the catalyst and permanently reduce sensitivity. Inhibition is temporary: hydrogen sulphide and halogenated hydrocarbons are absorbed by the catalyst, and in most cases the sensor recovers after a period of operation in clean air.

The MICROpeL 75C is specified with resistance to H2S poisoning and superior silicone resistance. Honeywell advises suitable protection where poisons or inhibitors may be present, and its safety note requires a bump check with target gas before each use of the sensor or instrument, so that correct operation is confirmed before the device is relied on.

Request a Quote for Honeywell SR-W-MP75C MICROpeL Combustible LEL Sensor

Seven Star LLC invites facility engineers, HSE managers, and procurement teams across Oman and the GCC to submit a formal RFQ for the Honeywell SR-W-MP75C MICROpeL replacement combustible sensor. With engineering support in Muscat, Seven Star LLC supplies on request with lead time confirmed at quotation, provides full technical datasheets on request, and offers direct access to our instrumentation division for calibration and fleet-support guidance. Contact Seven Star LLC today to secure genuine Honeywell gas detection spares with manufacturer-backed quality assurance.

Related Products

• MEDC SM87 | Hazardous Area Beacon | ATEX Beacons Zone 1 & Zone 2 Steady Beacons LU1/LU3 Ex d
• Dräger Polytron 7000 Gas Detector
• Oldham IR Gas Detector OLC100 / OLCT 100
• MSA General Monitors S5000 Gas Monitor
• Dräger Pac 8000 Single-Gas Detector
• Simtronics DM-TV6-T Flame Detector
• Industrial Scientific Ventis Pro5 Multi-Gas Monitor

Also available: Honeywell Sensepoint XRL Fixed Gas Detector