Combustible & Flammable Gas Detection and Gas Monitoring for Loss Prevention and Personnel Safety

Combustible and flammable gas detectors by Sensidyne are designed for process leak detection, loss prevention and personnel protection. Sensidyne equipment provides maximum reliability with an instrument that is the easiest to install and use while significantly lowering maintenance frequency and costs. 

A complete combustible gas detection system often includes both point gas monitors and open path gas detection. As the name implies, point detectors monitor specific areas or process equipment where gas leaks are most likely, and can pinpoint a leak by virtue of location. The actual placement of point gas monitors varies considerably. For information regarding sensor placement see our Gas Detection Knowledge-base article titled Sensor Placement for Point Gas Monitors. 

The second type of fixed gas detection is open path (OPGD). These systems are designed to monitor a long path or the perimeter of a process or unit for a large gas release. Enhanced laser diode spectroscopy (ELDS) open path gas detectors use a laser to traverse the area and detect gas  at low ranges without interference. ELDS Open path detection is very fast, molecular specific (e.g. Methane), can do two or more gases in the same unit (e.g. Methane and Hydrogen Sulfide) and covers up to a 650 foot path.

Installation costs can add up quickly. A SensAlert PLUS unit has an intrinsically safe certified sensor head so that it can be remote from the transmitter using cable only in Class I, Division 1 areas. The transmitter itself can also be installed intrinsically safe so that rigid conduit is not required. SensAlert is available in 2 or 3-wire versions, with relays and communication options to provide for seamless integration into your plant control system.

Reliability is assumed with a third party approved device, however there is much more to this issue. SensAlert products meet the performance requirements, and perform continuous self diagnostics, and time stamp all data and events including the last calibration and alarms including TWA. SensAlert intelligent sensors have non-volatile memory for all application information including the latest calibration and remaining sensor life. Fault currents for various types of failures may be configured for up to 6 current levels, providing more failure information.

Maintenance time and expenses, better known as the cost of operation is no longer taken for granted. Shop sensor calibration and hot-swapping in a classified area without a hot work permit is quite an advance in productivity, particularly when troubleshooting. Most Sensidyne sensors have annual, semi-annual or quarterly maintenance intervals. The ability to set the 4-20 mA loop to a specific value or to trim the zero (4mA) or the span (20 mA) is invaluable during commissioning. A large bright LCD display and non-intrusive menu-driven interface complete this state-of-the-art area monitor.

Click Here for a Reference Chart of Flammable Gases and Vapors 

What to Look for in a Combustible Gas Detector

Combustible Point Gas Monitor

When specifying a point gas monitor for your plant or facility it is important to consider 3 stages of use; installation, use and maintenance.

Installation

Additional costs can quickly add up when installing a point gas monitor. Make certain that the instrument you specify is easy to install and provides you with flexibility such as on board programmable relays, 2 or 3 wire units, a remote mountable sensor head and communication options.

Use

Using a gas detector should not be difficult, make sure your detector has a non-intrusive user interface, a large easy to read screen and a user-friendly menu structure. Point gas monitors that use transportable calibration and store operating parameters on the sensor such as default alarm levels, TWA, gas type and range streamline use of the monitor. Carefully specifying these options will ensure daily use of the monitor is easy for users of all experience and technical levels.

Maintenance

Maintaining point detectors can be cumbersome if the instrument is not designed with the user in mind. Look for an instrument that has a functional sensor check built in which the transmitter has the ability to perform a bump test on the installed sensor. Make sure the system uses Smart Sensor Technology with transportable calibration that stores sensor data in non-volatile memory on the sensor and with the ability to review the last calibration date, sensor life and diagnostic information from the transmitter screen.

Discover SensAlert Plus - The Advanced Point Gas Monitor, Click Here.

Open Path Gas Detector

When specifying an open path gas detector for your process or facility consider these aspects to ensure optimum protection, reliability and ease of use.

Low Level Detection

Traditional NDIR open path gas detection limits are 0.5 LEL Meter. Senscient ELDS open path can detect Hydrocarbons down to single digit PPM Meter levels. Detection at these low levels provides added time to initiate hazard mitigation measures. And, ELDS can detect toxic and flammable gases in the same unit!

Harmonic Fingerprint™

Patented Senscient techniques employ Harmonic Fingerprinting which enables interference-free identification of the target gas (and ONLY the target gas!) with a typical response time of a 1 – 3 seconds to T-90

Remote Functionality Tests

Test filters and gassing cells are traditional methods of testing previous generation open path gas detectors, which requires a technician to be physically present. Senscient ELDS open path gas detection uses a patented method of remote functionality verification known as SimuGas™. Since SimuGas can be performed remotely from the control room via 2-way HART communications, technicians are not required to physically visit the unit to perform functional testing and it can be done at any time.

Performance Approval

Senscient ELDS open path has been hazardous area approved and also certified to the latest FM and ATEX performance standards. No others can meet this standard.

To learn more about Senscient ELDS Open Path Gas Detection Click Here.

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Flammable Vapors & Gases Reference Chart

1 Density is relative to air of 1.0. Position sensors accordingly. From NFPA 325
2 TWA: Threshold Limit Value for the Time Weighted Average concentration for an 8 hour workday of a 40 hour work week, to which a worker can be exposed continuously without adverse affect.
Flash Point is the lowest temperature a flammable mixture can exist above the liquid.
LEL is the lowest percent by volume at which ignition can occur. From NFPA 325.
STEL: Threshold Limit Value for the Short Term Exposure Limit, typically 15 minutes, to which a worker may be exposed without ill affects.
UEL is the percent by volume above which burning cannot occur. From NFPA 325.
OSHA PEL: Same as TLV-TWA definition but regulated by law. See 29 CFR 1910.1000, Tables Z1 and Z2.
Water solubility may be important when a sample system is used. From NFPA 325.
3 NFPA 30, Chapter 1, Paragraph 1.7.3.2, Definition and Classification of Liquids.
4 CFRs are available at www.access.gpo.gov/nara/cfr/cfr-table-search. NFPA standards are at www.nfpa.org.
5 Threshold Quantity: The amount of a chemical that can be present before being required to comply with OSHA 29 CFR 1910.119A, Process Safety Management, or the EPA Risk Management Program, 40 CFR 68.130.
Terms - n/a: not applicable, - -: not given, Gas: Substance is a gas at normal ambient temperature range.
6 P: Substance polymerizes, use Infrared instead of catalytic sensor.

Note: The user of this table is responsible for verifying the accuracy of the compiled information!