Personal Ozone Monitor Manual Rev. E-2
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11.2. Equipment Required
The equipment that is needed to carry out the calibration is commercially available, or
it can be assembled by the user. Calibration using a primary ozone standard involves
the generation of ozone concentrations that are simultaneously measured by a
primary ozone standard and the instrument undergoing calibration. This procedure
requires the following equipment:
1. Zero air source
2. Ozone generator
3. Sampling manifold (inert material such as PTFE or FEP only)
4. Sampling lines (inert material such as PTFE or FEP only)
5. UV Photometer
Use of a certified transfer standard for calibration involves the generation of ozone
concentrations, using the calibrated ozone generator, that are measured by the
instrument undergoing calibration. This procedure requires the following equipment:
1. Zero air source
2. Certified Transfer Standard
3. Sampling manifold (inert material such as PTFE or FEP only)
4. Sampling lines (inert material such as PTFE or FEP only)
Zero air can be generated either from compressed cylinders or from scrubbed ambient
air. If ambient air is used, contaminants such as ozone and nitric oxide must be
removed. Detailed procedures for generating zero air are in the EPA’s
Technical
Assistance Document for the Calibration of Ambient Ozone Monitors
.
11.3. Instrument Preparation
Prior to calibration, follow the steps below:
1. Turn on the Personal Ozone Monitor and allow it to stabilize for a minimum
of one hour.
2. Connect the instrument to the manifold on the ozone calibration setup. If a
particle filter will be used in normal operation, the calibration must be
performed through the filter. The manifold must be vented to atmosphere
so that pressure does not build up in the calibration setup. Connection of
the POM directly to a pressurized output of any device can damage the
Personal Ozone Monitor.
3. Verify that the flow rate into the manifold is greater than the total flow required
by the instrument and any other flow demand drawing from the manifold.
11.4. Calibration Setup Preparation
As indicated in the EPA Technical Assistance Document there are several tests that
should be performed prior to calibration to ensure the accuracy of the measurements.
These tests include:
