Lower Explosive Limits Formulas:

Simple: LEL Reading x CF = Actual % LEL

Entry Team Turn Back: Desired % LEL Reading (i.e. 25%) ÷ CF = Actual LEL meter Reading

Obtain 10% LEL: PLEL x 10,000 ÷ 10 = 10% LEL in PPM

Convert meter % to PPM: LEL Reading % x CF x PLEL% ÷ 100 x 10,000 = PPM

Predict LEL Reading: 1300 Rule Predicted PPM ÷ (CF x PLEL x 100) = Predicted % Meter Reading