Testing of New Ozone Photometers

1
Testing of New Ozone Photometers

• Ozone Transport Commission/MANEVU
• Fall Meeting
• November 14, 2013
• Washington, DC
• Will Ollison

2
Testing of New O3 Photometers

• Do we know what the O3 monitors really
  measuring?
• EPA currently certifies FEM photometers with up
  to 60 ppb interference bias, 24-hour zero/span
  drifts of 20 ppb, LODs of 10 ppb, and noise
  levels of 5 ppb but notes in the 2013 ISA (EPA
  600/R-10/076F) that these criteria should be
  revised to more accurately reflect the necessary
  performance requirements for O3 monitors used to
  support the current NAAQS.
• NIST staff notes (Norris et al. 2013 JAWMA 63
  565-574) that regular audits currently provide
  reliable measures of field monitor precision and
  bias in response to challenges of O3 in zero air,
  although not of sample matrix effects arising
  from ambient humidity and interfering species
  (Spicer et al. 2010 JAWMA 60 1353-1364).
• New monitor testing suggests actual NAAQS
  attainment is better than reported and affordable
  photometer scrubber upgrades will improve O3
  measurement accuracy Ollison et al. 2013 JAWMA
  63 855-863 Johnson et al. 2013 JAWMA (in
  press).

3
Ozone Monitor Types

• EPA is currently evaluating the NO-scrubbed 2B
  Technologies 211 photometer and the Teledyne-API
  265E NO-O3 chemiluminescence monitor as potential
  new ozone Federal Reference Methods

4
Percent O3 Monitor Share U.S. Network (1990-2011)
5

• TE49C-211 Hourly Difference Collocated NO VOCs

Ollison et al. (2013) JAWMA 63 855-863.
6
211 ME Factor (211F) 205-211 Difference (205D)
Home Activity

• Johnson et al. (2013) JAWMA (in press)

7
GPT Scrubberless Module

• Drop-in NO-scrubbers are commercially available
  from 2B Technologies to convert Teledyne-API
  Thermo photometers to interference-free (H2O,
  Hg, aromatic VOCs) O3 monitors.