Oldham OLCT 100 Fixed Gas Detector

Overview

The Oldham OLCT 100 is a compact fixed gas detector transmitter engineered by Teledyne Oldham Simtronics to continuously monitor combustible, toxic, refrigerant, or oxygen gases in demanding industrial environments. Built around an interchangeable sensor-head architecture, the OLCT 100 supports catalytic oxidation, infrared, electrochemical, MEMS, and semiconductor detection technologies within the same rugged epoxy-coated aluminium or 316L stainless steel housing, letting one platform cover a wide catalogue of target gases and measurement ranges without switching transmitter families. The detector connects exclusively to Oldham analog controllers over a 4-20mA loop, and its explosion-proof (XP) and intrinsically safe (IS) variants are ATEX and IECEx certified for Zone 1/Zone 21 and Zone 0/Zone 20 respectively, making the OLCT 100 a dependable first line of defence in refineries, chemical plants, and other Group IIC hazardous areas.

As the official authorized partner and exclusive regional representative for Oldham, Seven Star LLC proudly supplies the Oldham OLCT 100 gas detector to facility engineers, EPC contractors, and plant operators across the Sultanate of Oman and the wider GCC. Customers benefit from genuine Teledyne Oldham Simtronics hardware, calibrated commissioning support, and locally held spares, backed by our instrumentation division’s field experience in Muscat, Sohar, and Salalah industrial zones.

Measurement and Operating Principle of the Oldham OLCT 100

Depending on the target gas, the Oldham OLCT 100 uses one of five detection principles selected to give the best accuracy and reliability for that specific application. The catalytic bead version oxidizes combustible gas on a heated pellistor element, producing a resistance change proportional to LEL concentration from 0 to 100% LEL. The electrochemical version relies on a controlled redox reaction between the target toxic gas or oxygen and an internal electrolyte, generating a current directly proportional to concentration for gases such as H2S, CO, Cl2, NH3, and NO2. The infrared (XPIR) version passes light through the sample volume and measures absorption at a wavelength characteristic of CH4, CO2, SF6, or common refrigerant blends, while the MEMS and semiconductor variants use solid-state sensing elements suited to hydrogen and other combustible gases requiring fast, drift-resistant response.

In every configuration, the sensing element continuously outputs a 4-20mA analog signal to a compatible Oldham controller, which applies alarm thresholds, fault diagnostics, and SIL 2 logic per IEC 61508 and EN 50402:2017. Because the sensor head is field-replaceable, routine maintenance means swapping a calibrated cartridge rather than removing wiring or re-certifying the transmitter body, which keeps mean time to repair low and avoids re-opening the explosion-proof enclosure more than necessary. The practical result for the plant is continuous, self-diagnosing coverage with no moving parts to wear out and no risk of the sensing element itself becoming an ignition source in a classified area.

Engineering Design of the Oldham OLCT 100

The Oldham OLCT 100 housing is epoxy-coated aluminium as standard, with a 316L stainless steel option for marine, purification, and food-processing environments exposed to corrosive atmospheres. Dimensions range from roughly 135 x 133 x 84mm for the catalytic and standard electrochemical bodies up to 179 x 138 x 84mm for the MEMS, infrared, and high-temperature variants, with unit weight between 0.95kg and 1.8kg depending on sensor type. The enclosure is rated IP66 across the entire range, and cable entry is offered in M20 or 3/4-inch NPT threading to match regional wiring practice, with a shielded three-wire cable standard on most variants and a two-wire option on the infrared and semiconductor models.

Installation is straightforward: the OLCT 100 mounts via its integral junction box using the four corner bosses, with an optional wall or ceiling mounting bracket, protective weather cover, and calibration cup available as accessories for field commissioning. The high-temperature (HT) version separates the transmitter body from the sensor using a heat-resistant cable in 5, 10, or 15-metre lengths, allowing the electronics to sit in a cooler zone while the sensor itself tolerates process temperatures up to 140°C. Because the OLCT 100 communicates over a simple analog 4-20mA loop back to the Oldham controller rather than a proprietary digital bus, wiring and commissioning at the panel stay consistent across a large detector count, which simplifies both new installations and retrofits into an existing Oldham detection network.

Key Features

The Oldham OLCT 100 combines detection flexibility with certified safety performance, and buyers evaluating the Oldham OLCT 100 against competing transmitters should note the following capabilities that define its role in a fixed gas detection network:

• Detects combustible gases, a broad range of toxic gases, refrigerants, and oxygen using a single interchangeable transmitter platform.
• Supports catalytic, infrared (XPIR), electrochemical, MEMS, and semiconductor sensor technologies matched to the target gas.
• SIL 2 certified per IEC 61508 and EN 50402:2017, verified by INERIS for high-reliability safety instrumented functions.
• ATEX and IECEx certified for Zone 1/Zone 21 (XP versions) and Zone 0/Zone 20 (IS version), covering Group IIC hazardous areas.
• IP66-rated epoxy-coated aluminium housing, with a 316L stainless steel option for corrosive or marine duty.
• Standard 4-20mA analog output for direct connection to Oldham fixed gas controllers.
• High-temperature (XP HT) variant supports remote sensor placement up to 15 metres for process temperatures to 140°C.
• Field-replaceable sensor cartridges minimise downtime and avoid unnecessary opening of the explosion-proof enclosure.

Industrial Applications

Site teams selecting the Oldham OLCT 100 for a new installation will find it deployed across steel mills, petrochemical facilities, chemical processing plants, pharmaceutical manufacturing, food and beverage production, refrigeration plants, and wastewater treatment works, wherever a continuous, certified point of gas detection is required at a compressor skid, tank farm, process unit, or confined space entry point. Its interchangeable sensor range means the same transmitter body can be specified for methane monitoring on a biogas digester, hydrogen sulfide monitoring in a wastewater lift station, or refrigerant leak detection in an ammonia or HFC chiller plant, simplifying spares holding for multi-site operators.

As the officially authorized partner for Oldham, Seven Star LLC distributes and supports the OLCT 100 throughout Oman and the GCC, serving oil and gas facilities, district cooling plants, desalination sites, and industrial zones including the Sohar and Salalah free zones. Our team assists with sensor selection against the target gas list, ATEX zone classification review, and coordination with existing Oldham controller networks so that new detector points integrate cleanly into a facility’s established fire and gas system.

Technical Specifications

The table below summarizes the core specifications of the Oldham OLCT 100 fixed gas detector, the reference point procurement teams use when comparing the Oldham OLCT 100 against alternative fixed gas transmitters, across its standard variants.

Request a Quote for Oldham OLCT 100 Fixed Gas Detector

Facility engineers and procurement teams in Oman and the GCC evaluating a fixed gas detector for a hazardous area project can request a formal RFQ for the Oldham OLCT 100 directly from Seven Star LLC, with regional warehouse stock, full technical datasheets, and application support from our instrumentation division available on request. As the authorized partner for Oldham in Oman and the GCC, Seven Star LLC ensures every OLCT 100 supplied is genuine Teledyne Oldham Simtronics hardware backed by manufacturer warranty, calibration gas support, and local commissioning assistance from Muscat to Sohar and Salalah.

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