Your SlideShare is downloading. ×
Correction factors basics
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×
Saving this for later? Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime – even offline.
Text the download link to your phone
Standard text messaging rates apply

Correction factors basics

3,580
views

Published on

Published in: Technology

0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
3,580
On Slideshare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
63
Comments
0
Likes
0
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide

Transcript

  • 1. Correction Factors LEL & PID Paul Tarter Regional Sales Manager RAE Systems
  • 2. What is a Correction Factor?
    • Correction Factor (CF) is a measure of the sensitivity of the LEL/PID sensor to a specific gas
    • CFs are scaling factors, they do not make a LEL/PID sensor specific to a chemical, they only correct the scale to that chemical.
    • Correction Factors allow PID calibration on cheap, non-toxic “surrogate” gas .
    • Ref: RAE handout TN-106/TN-156
  • 3. Catalytic LEL Sensor Response
    • When a LEL monitor is calibrated to a gas (i.e. methane) it always thinks it is seeing methane.
    • Like a truck that is designed to use a specific size of tire
    • That size tire is calibrated to the speedometer.
  • 4. Catalytic LEL Sensor Response
    • If your monitor calibrated for methane is exposed to gasoline
    • It would be like putting a different size tire on that truck and not adjusting the speedometer.
    • It will still show a speed, but it will not be accurate
  • 5. LEL Correction Factors
    • LEL Correction Factors
      • Acetone 2.2 CF
      • Ethanol 1.7 CF
      • Gasoline 2.1 CF
      • Jet Fuel JP-4,-5,-8 3.4 CF
      • Propane 1.6 CF
      • (RAE Systems TN-156)
  • 6. PID Correction Factors 8 9 10 11 12 13 14 15 8.4 9.24 9.54 9.99 10.1 10.5 10.66 11.32 11.47 12.1 14.01 Benzene MEK IPA Ethylene Acetic Acid Methylene chloride Carbon Tet. Carbon Monoxide Styrene Oxygen Ionization Potential (eV) 11.7 eV Lamp 10.6 eV Lamp Not Ionizable 9.8 eV Lamp
  • 7. CF Example: Toluene
    • Toluene CF with 10.6eV lamp is 0.5 so PID is very sensitive to Toluene
    • If PID reads 100 ppm of isobutylene units in a Toluene atmosphere
    • Then the actual concentration is 50 ppm Toluene units
    • 0.5CF x 100 ppm iso = 50 ppm toluene
  • 8.  
  • 9. Question?

×