An automated method for preparing and calibrating electrochemical concentration cell (ECC) ozonesondes
Abstract. In contrast to the legacy manual method used to prepare, condition, and
calibrate the electrochemical concentration cell (ECC) ozonesonde, an
automated digital calibration bench similar to one developed by MeteoSwiss
at Payerne, Switzerland, was established at NASA's Wallops Flight Facility
and provides reference measurements of the same ozone partial pressure as
measured by the ECC. The purpose of an automated system is to condition and
calibrate ECCs before launching on a balloon. Operation of the digital
calibration bench is simple and real-time graphs and summaries are available
to the operator; all information is archived. The parameters of interest
include ozone partial pressure, airflow, temperature, background current,
response, and time (real and elapsed). ECCs, prepared with 1.0 %
solution of potassium iodide (KI) and full buffer, show increasing partial
pressure values when compared to the reference as partial pressures
increase. Differences of approximately 5–6 % are noted at 20.0 mPa.
Additional tests with different concentrations revealed the Science Pump
Corp. (SPC) 6A ECC with 0.5 % KI solution and one-half buffer agreed
closer to the reference than the 1.0 % cells. The information gained
from the automated system allows a compilation of ECC characteristics,
as well as calibrations. The digital calibration bench is recommended for
ECC studies as it conserves resources.