Combustible Gas Monitor detects MBTE and THF.

Press Release Summary:

Ultima® IR Gas Monitor detects tetrahydrofuran (THF) and methyltertiarybutylether (MBTE). Its calibrator and controller send digitally encoded signals for non-intrusive calibration and access to monitor features. Suitable for paints and coatings (THF monitoring) and petrochemical (MBTE monitoring) industries, monitor offers complete calibration and self-contained record. Available for use with Ultima® Plus Digital Network System, gas monitor includes Replace Sensor indicator.

Original Press Release:

MSA Ultima® IR Combustible Gas Monitor Expands Capabilities

The MSA Ultima® IR Combustible Gas Monitor is now able to detect tetrahydrofuran (THF) and methyltertiarybutylether (MBTE). Designed with highly reliable, advanced IR technology and easy-to-use features, the monitor is rugged, compact and easy to calibrate. It is ideal for use in the paints and coatings (THF monitoring) and petrochemical (MBTE monitoring) industries, among others.

The Ultima IR Gas Monitor's unique IR sensing element simply plugs into the Ultima, as do the other sensors in the Ultima family. It offers complete calibration (without manual intervention) and a self-contained record of the latest calibration date and time. The optional auto-calibration module permits permanent gas connection and calibration at designated time intervals.

All Ultima Gas Monitors are available for use with the Ultima® Plus Digital Network System. This allows for easy connection of Ultima Monitors over a single communication line, reducing installation and maintenance costs. In addition, the monitors provide a local display of gas concentrations (minimum, maximum and average), output signals and alarm indications.

A "Replace Sensor" indicator alerts the user to replace the plug-in sensor. Relay outputs with two alarm levels become available when the internal relay option is selected. The Ultima Calibrator and Controller send digitally encoded signals for non-intrusive calibration and access to advanced monitor features, eliminating the need to open the enclosure during installation, set-up or calibration.

For more information on the Ultima IR Gas Monitor request literature #07-2026 by dialing 1-800-MSA-4678, or contact your nearest MSA sales representative. To learn about MSA and our other high quality products, visit our web site at

Ultima® IR Combustible Gas Monitor

The Ultima IR Gas Monitor is a compact, highly reliable, combustible gas monitor. The monitor is based upon proven infrared (IR) sensing technology. The unique design provides the IR sensor in a small, explosion-proof module. This module is fully compatible with the widely used and accepted Ultima sensor/transmitter platform. The small gas diffusion volume is designed to provide quick speed of response, and maximum protection from the harsh environmental conditions.

Continuous lower explosive limit (LEL) gas detectors must operate in a variety of ambient conditions. IR technology is immune to the poisoning effects of certain compounds and is not affected by oxygen-deficient conditions. The Ultima IR Gas Monitor will operate unattended for long periods of time without maintenance in ever-changing environmental conditions. The Ultima IR Gas Monitor is designed for extended, trouble-free operation, with minimal zero drift over the rated temperature range.

o Field-proven infrared gas detection technique
o Easy to install, operate, and maintain
o "Fail to Safety" operation
o No poisoning effects by back-ground compound(s)
o Automatic compensation for humidity & temperature changes
o Operates in high-gas and/or low-oxygen environments
o Compatible with Ultima add-on accessories (relays, pumps, etc.)

How the Ultima IR Gas Monitor Works
Hydrocarbons and many other gases absorb infrared light energy at defined wavelengths, providing an absorption signature for each gas. The Ultima IR Gas Monitor has one infrared light source which is directed through two different wavelength filters. One light beam is used as a reference and measures IR intensity outside of the hydrocarbon absorption range. The other IR beam is the target gas beam, and it traverses the gas diffusion volume in the signature wavelength of hydrocarbons. Each light beam is then directed to its corresponding detector, and the difference in IR intensity is proportional to the target gas concentration. If no target gas is present, the difference between detectors is zero, and the monitor outputs a zero gas reading. The dual-beam concept also minimizes zero drift and temperature variation.


o Internal Relay option provides 2 levels of alarm, plus a trouble-condition relay
o External Relay package provides 3 levels of alarm, plus a trouble condition relay
o Flow-through adapter for sample draw monitoring applications
o Duct-mounting kit

Optional Modules

Relay Module
Provides three levels of alarm relay outputs along with a normally energized trouble relay. See Data Sheet 07-2019.

Sampling Module
Provides a method to draw a gas sample into the Ultima IR detection chamber. See Data Sheet 07-2023.


AC Power Supply
For AC-powered operation of an Ultima IR Gas Monitor

Remote Sensor Assembly
Allows the IR sensing chamber to be separated from the transmitter for difficult-to-reach installations.

Duct Mount Kit
Provides an easy method to install an Ultima Gas Monitor in a ventilation duct

Flow Cap
Used when an Ultima Sampling Module or any other type of flow system is providing the gas sample to an Ultima Gas Monitor.

See Data Sheet 07-2022 for all Ultima Accessories.

Ordering Information

All Ultima Gas Monitors are manufactured using MSA's unique Assemble-To-Order (ATO) process.


Typical Gases: C1-C7 hydrocarbons
Ranges: 0-100% LEL
Repeatability: < ± 2% FSD for 0-100% LEL
Operating Temperature: -20° to +50°C
Operating Humidity: 0-95% RH non-condensing
Stability: ±5% FSD/year
Linearity: <± 2% FSD
Warm-up Time: 30 seconds
Response Time: T90 <30 seconds
Output: 4-20 mA current sourcing or digital (DAN 2001)
Power: 24VDC nominal (10-30VDC) 200mA max. current draw - standard unit
410 mA max. current draw - with relays
Enclosure: Rated for both NEMA 4X and Class 1, Div 1, Group B, C & D
Gland Entries: (1) 3/4" NPT
Physical Size: 5.25" W x 4.5" D (13.3 cm x 11.4 cm)
Weight 4.5 lb. (2.04 kg)
With Internal Relays:
Size 5.25" W x 5.5" D (13.3 cm x 14.0 cm)
Weight 5.0 lb (2.27 kg)
Warranty: 2 years

More from Thermal & Heating Equipment

All Topics