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 [...]
Predicting Lower Explosive Limit meter readings: Multiply the Conversion Factor (CF) times the Published Lower Explosive Limit (PLEL) times 100 = ? CF x PLEL x 100 = ? Divide ? into the maximum achievable PPM from the 1300 rule Example: Propenol's CF for LEL is 2.1%, PLEL is 2.5%, vapor pressure is 17mmHg vp [...]
LEL Meter Prediction: vp = 33 mmHg, LEL CF = 2.2, PLEL = 2.0% Which of the following is the correct predicted LEL meter reading for this material? 33 x 1300 = ? CF x PLEL x 100 = ? ? ÷ ? = predicted meter LEL reading
LEL Meter Prediction: Normal butyl alcohol (n-butanol) vp = 6 mmHg, PLEL = 1.4%, LEL CF = 2.8. Which of the following is the correct predicted LEL meter reading for n-butanol?
LEL Meter Predictions: Known chemical vp = 3 mmHg, PLEL = 1.2%, LEL CF = 2.5 (per manufacturer's spec's) Which of the following is the correct predicted LEL meter reading for this chemical?
Predicting PID, O2 and LEL Readings: PID formula for predicting is: vp x 1300 ÷ CF = ? O2 formula for predicting is: vp x 1,300 = ? ÷ 50,000 = O2 drop (20.9% - O2 drop) LEL formula for predicting is: (step #1) vp x 1300 = ? (step #2) CF x PLEL X [...]
Predicting PID, O2 and LEL Readings: PID formula for predicting is: vp x 1300 ÷ CF = ? O2 formula for predicting is: vp x 1,300 = ? ÷ 50,000 = O2 drop (20.9% – this O2 drop) LEL formula for predicting is: (step #1) vp x 1300 = ? (step #2) CF x PLEL [...]
Predicting meter readings: Use the NIOSH Pocket Guide, WISER, this App or some other reference to look up values for isopropyl alcohol (2-propanol). This meter's manufacturer indicates PID CF is 6.0 & LEL CF is 2.2. Which of the following is the correct predicted PID, O2 and LEL meter readings for isopropyl alcohol (IPA)?
You are the science officer on a known spill of approximately 55 gallons of triethylamine. The material is in a confined room @68°F. All electrical, HVAC and ingress/egress have been secured. What are the predicted meter readings for PID, O2 and LEL? 1. PID 78,000 PPM O2 19.5% LEL 234% 2. PID 78,000 PPM O2 [...]
In reference to question #22, you have determined that the predicted LEL is 234%. TEA has an LEL of 1.2% and a UEL of 8%. Which of the following is correct? 2.5 CF x 1.2 PLELx 234% ÷ 100 = 7.02% 1. 7% is below the LEL 2. 7% is above the UEL 3. 7% [...]