PID 1. Simple: PID reading x CF = Actual PPM present of chemical. 2. Entry team turn around: Desired reading (e.g. IDLH) on PID ÷ CF = Reading on the PID. 3. Entry team turn around based on desired LEL: Desired reading (e.g. 25% LEL). PLEL% x 10,000 ÷ 25 = 25% LEL in PPM. [...]
Suggested Monitoring Order: 1. Radiation 2. Corrosive 3. Oxygen 4. Flammable 5. Toxic
Suggested action for explosive atmospheres: <10% LEL continue investigation 10% - 25% LEL continue with extreme caution >25% LEL withdraw immediately (implement engineering controls such as ventilation etc.)
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% [...]
Oxygen: Meter % Drop to PPM: 20.9% - Actual Reading% x 5 x 10,000 = PPM Drop Predicted O2 Reading: 1300 Rule PPM for Known Chemical ÷ 50,000 = Predicted drop Subtract Predicted Drop from 20.9% = Predicted % O2 Meter Reading
P.I.D.: Simple: PID Reading x CF = Actual PPM Present in Atmosphere Entry Team Turn Back: Desired Reading on PID ÷ CF = Reading on PID in PPM Predicted PID: 1300 Rule for Known Chemical PPM ÷ CF = Predicted Maximum PID Reading in PPM Obtain 10% LEL in PPM: PLEL x 10,000 ÷ 10 [...]