How is LEL typically measured in the field?

LEL, or Lower Explosive Limit, refers to the lowest concentration of a gas in air that can ignite and produce a flame. In the field, LEL is commonly measured using a gas detector, which consists of sensitive sensors designed to detect and quantify the concentration of flammable gases in the atmosphere. These detectors often provide real-time readings and can alert users when the concentration approaches the lower explosive limit, thus enabling safety measures to be taken to prevent potential explosions or fires.

Other instruments like spectrophotometers, centrifuges, and thermometers serve different purposes and are not suited for measuring flammable gas concentrations. A spectrophotometer is used for measuring light absorption and chemical concentrations in solutions, a centrifuge is designed for separating substances based on density, and a thermometer measures temperature, none of which are applicable for measuring LEL in the field.