Short name:
RHTO3NOx

Full name:
RH, T, Ozone, NOx Combined Instrument (Seinfeld)

What is being measured:
Relative humidity (RH), Temperature (T), Ozone (O3), Nitrogen oxides (NO + NO2, NOx)

Sampling Protocol:
Online

Manufacturer:
Vaisala, Horiba, Teledyne

Model:
Vaisala HMM211, Horiba APOA-360, Teledyne 200

Instrument year :
None specified

Data recording software:
Labview custom program

Data analysis software:
None

Raw data time resolution:
1 min

Analysis data averaging:
None

Detection limit:
1 ppb for Ozone, 0.5 ppb for NOx

Sensitivity to temperature (and correction method, if applicable): :
None

Sensitivity to relative humidity (and correction method, if applicable): :
NOx instrument is sensitive to RH, takes about an hour to re-equilibrate

Sampling method:
Direct sampling

Sample preparation method:
None

Sample residence time (chamber to instrument) (seconds):

Length of tubing (cm):
30

Instrument flow rate:
1 LPM

Tubing inner diameter:

Tubing material:
FEP Teflon

Chemical identification method:
Ozone by UV absorption spectroscopy, NO by chemiluminescence upon reaction with ozone, NO2 by conversion to NO on a heated molybdenum catalyst. RH/T aren't chemicals.

Data analysis method:
None

Quantification method:
Instrument automatically applies calibration.

Calibration method:
Calibration of O3/NOx with standard gases. Calibration of RH with saturated salt solutions in the range of 11-90%.

Calibration drift estimate:

Calibration schedule:

Uncertainty estimation method:
Inquire with PI

Known interferences:
Ppm levels of H2O2 interferes with ozone measurement (small amount). NOy species (like PANs, org. nitrates, N2O5, etc.) interferes with NOx measurement as it's read as NO2.

Link to supplemental information:

Additional notes:

Measurement uncertainty:
Uncertainty in ozone is 10%, NOx is 20%, T/RH is 10%

Measurement units:
T (Celsius), RH (%), Ozone (ppb), NOx (ppb)