| Gas detectors can be found in all walks of life, from | | | | 100% LEL is the lowest concentration at which a |
| food processing plants to parking garages, from | | | | flammable substance can produce a fire or explosion |
| airplanes to casinos. Any place that can have a | | | | when ignited. |
| potential lack of oxygen or presence of a toxic gas | | | | UEL (Upper Explosive Limit) is the maximum |
| needs a gas detector present to monitor the safety | | | | concentration of gas in air that will burn. |
| of people. Some common uses during field projects | | | | Each compound (gas) has a different LEL, or the |
| are: confined space entry, well drilling, soil screening, | | | | point at which the compound will burn or become |
| area mintoring, worker safety, indoor air quality, and | | | | explosive. |
| leak detection. Gas detectors have a variety designs; | | | | Most flammable compounds become explosive at |
| pager size units, handheld datalogging units, Stand | | | | less than 5%(vol). |
| alone area monitors, and wall mount fixed | | | | Each gas has a different LEL and UEL. |
| systems.Here are some gas detection basics: | | | | %Gas is the highest unit of measurement, which is |
| 1ppm is one part in 1,000,000 parts.Generally ppm | | | | the amount of pure gas. |
| (parts per million) is the lowest unit of measurement | | | | How Do Gas Detection Sensors Work? |
| 10,000ppm = 1% by Volume | | | | The Oxygen Sensor is an electochemical sensor. Any |
| LEL is the next unit of measurement. It is a | | | | gas which can be oxidized or reduced |
| percentage of the explosive %(vol) level of a | | | | electrochemically can be detected by means of a fuel |
| compound. | | | | based electrochemical sensor. |