Whether it’s an offshore oil rig or large refinery, oil and gas companies know they must be careful to monitor gas levels on a continual basis in order to protect their employees and facilities. If such gases as hydrogen, methane, benzene, or others reach dangerously high levels, they can ignite and lead to potentially catastrophic events. To make sure this does not happen, it’s vital to have the correct type of flammable gas detector at your facility. However, because there are various types of flammable gas detection systems, choosing the right one can be a tough decision. But if you have the most up-to-date facts about these monitors, the decision can be much easier.

Fixed or Portable?

When it comes to flammable gas detection, one of the first decisions to make is whether you need fixed monitors, portable monitors, or both. In most companies, a combination of both monitors is used to provide 24/7 protection. Fixed monitors, which are installed in a certain area and can offer continual analysis of air levels, provide 24/7 monitoring and are considered vital to overall safety. A portable flammable gas detector, often used in confined spaces, lets workers test areas before entering, giving them an early warning as to when dangerous conditions may be present. Small in size, these monitors are easy to transport and can be used in a variety of situations.

Open Path or Point?

Along with deciding between fixed or portable monitors, it’s also important to distinguish between open path or point detectors. Measuring the concentration of the gas at the sampling point of the instrument, they can use various levels of measurement such as volume ratio, lower explosion limits (LEL), or PPM for lower-level concentrations. Although used in many situations to detect toxic gases, they are primarily made for flameable gas detection.

Sensor Type

Because there are many types of sensors that are used in these gas monitors, it’s important to choose the right one for your facility. To guarantee the best results, make sure the gas monitor used can detect the correct type of gas, has an adequate range of concentration for the gas it will be monitoring, and can compensate for other gases that may be present which could alter the readings or damage the sensor.


For any fire or explosion to occur, combustible gases must combine fuel, oxygen, and an ignition source. Depending upon the specific fuel and oxygen mixture, the risks in a facility can vary. Therefore, gas monitors measure the percentage of these ignition sources using the criteria of LEL and UEL, which stand for Lower Explosive Limit and Upper Explosive Limit. Since each gas has its own LEL and UEL values, it’s important to have a monitor that is properly calibrated to measure these levels for the gases that may be present. By understanding LEL and UEL levels as well as the other criteria involved in these situations, choosing the correct monitor can be a much simpler decision.