MSA Ultima XIR Infrared Combustible Gas Monitor (legacy)

MSA Ultima XIR infrared combustible gas monitor explained

The MSA Ultima XIR is a fixed, explosion-proof infrared gas monitor in a 316 stainless steel housing, used to detect hydrocarbon vapours as a percentage of the lower explosive limit. It belongs to the Ultima family of MSA fixed monitors and uses infrared technology, which the manufacturer highlights as a way to avoid the need for frequent calibrations, and its operation compensates for temperature, humidity and ageing effects. The manufacturer now lists the Ultima XIR as discontinued and points to the Ultima X5000 as the alternative. Seven Star LLC is an independent supplier in Muscat and helps plants in Oman and the GCC find replacements and spares for installed Ultima XIR monitors; we are not affiliated with the manufacturer.

This page is written for maintenance and procurement teams who still have Ultima XIR units on site and need to understand what they are, what the HART output offers and how to plan a replacement.

Ultima XIR technical specifications

How the Ultima XIR detects gas

An infrared hydrocarbon sensor measures how much infrared energy a gas cloud absorbs at a wavelength where combustible molecules absorb strongly. The monitor compensates for temperature, humidity and ageing effects, which matters on exposed platforms and in humid coastal air where conditions swing widely through the day and the year. Output goes to the control system as a 4-20 mA signal, and the HART layer lets a technician read diagnostics and change settings from a handheld communicator.

Gases covered by the Ultima XIR

The manufacturer lists many hydrocarbons and organic vapours for this monitor, selected by gas code when ordering. Among them are methane, ethane, propane, butane, pentane, hexane, heptane, octane, ethylene, propylene, acetylene, gasoline, jet fuel, naphtha, methanol, ethanol, acetone, methyl ethyl ketone, aromatic solvents such as xylene and ethylbenzene, and carbon dioxide as an option. Because infrared response differs from gas to gas, the monitor must be set up and calibrated for the gas actually expected on site.

Replacing an Ultima XIR: the Ultima X5000 route

Plant owners often start by comparing the replacement with the original wiring before they compare anything else, because rewiring is the costly part. Plants that still run the Ultima XIR usually ask about a like-for-like successor. The manufacturer names the Ultima X5000 as the alternative, and Seven Star LLC lists an Ultima X5000 gas monitor separately in the catalogue. Before changing over, compare the cable entries, the hazardous-area classification on the tag, the 4-20 mA wiring (3-wire sourcing) and the HART configuration so the new head can use the existing conduit and loop. Also check the gas type, because the replacement is configured for the specific gas.

Selection and ordering checklist for the Ultima XIR

• Target gas and measuring range, or the equivalent gas code on the existing tag.
• Hazardous-area classification and approval shown on the nameplate.
• Output type: 4-20 mA 3-wire, with or without HART.
• Whether carbon dioxide detection is needed.
• Mounting arrangement and sensor spares on site.
• Calibration accessories such as the Ultima Calibrator or Ultima Controller, which the manufacturer lists for the Ultima family.
• Whether the monitor is staying in service or being replaced.

Commissioning and maintenance of the Ultima XIR

Commission each unit with a zero check in clean air and a span check with the correct gas, then confirm that the 4-20 mA value reaches the controller and the alarm set points behave as designed. The Ultima Controller and Ultima Calibrator listed for this family allow set-up, calibration and address changes without opening the housing. Keep the sensor face clean, check the junction and cable glands for water ingress after the rainy season and record calibration dates. Because the sensor can be replaced without declassifying the area, spare sensors can be fitted during a permit-controlled live job.

Typical Ultima XIR applications in Oman and the GCC

In Oman and the GCC the Ultima XIR has been used on oil and gas wellheads, compressor and pump areas, loading racks, gas turbine enclosures and storage tank farms, and in utility plants where hydrocarbon leaks are a risk. The stainless housing and wide temperature range suit outdoor service in coastal humidity and desert heat, provided the unit has a sunshade where direct radiation is high.

Information to send with an Ultima XIR RFQ

• Photo of the nameplate or the full Ultima XIR code
• Target gas, range and approval
• Output and HART requirement
• Quantity and whether replacement or spares
• Calibration gas and tools needed
• Delivery location and date

Storage, handling and spares for the MSA Ultima XIR

Store the MSA Ultima XIR and its sensors as described in the manufacturer instructions, in a clean, dry place within the stated temperature range. Some gas sensors have a limited shelf life, so plan deliveries close to the installation date. In Oman and the GCC, avoid storing detectors and calibration gas in hot containers or in direct sun.

• Bump test or calibrate the detector with certified test gas at the interval set by your site safety procedure.
• Check hazardous area certificates and markings against the zone classification before installation.
• Keep spare sensors, filters and calibration gas for planned maintenance.
• Record test and calibration results for each detector tag number.

When you send an RFQ for the MSA Ultima XIR, include the target gases, ranges, area classification and any calibration kit you need, so the full scope can be quoted together.

Documents and quotation

Send the Ultima XIR nameplate details and we will confirm which documents are available and whether the Ultima X5000 is a suitable replacement for your installation.

Seven Star LLC prepares quotations for MSA fixed gas monitors in Oman and the GCC as an independent supplier, with delivery arranged to your site.