Model 106-L Ozone Monitor Manual Rev. E
28
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:
Setup
check
Ozone loss test
Linearity
check
Intercomparison
test
Setup Check
A visual inspection of the calibration setup should be performed before
calibration to verify that the setup is in proper order. All plumbing connections
should be checked and verified to follow the manufacturer's instructions. Any
obvious leaks should be fixed and the manifold and sampling lines should be
checked for general cleanliness. For more information refer to the
manufacturer's User Manual for the primary ozone standard or ozone transfer
standard.
Ozone Loss Test
Some ozone may be lost in the calibration setup due to reaction with the walls
of the manifold and sampling lines. Any significant loss of ozone must be
measured and be subsequently applied to correct the calibration
measurements. For more information refer to the manufacturer's User Manual
for the primary ozone standard or ozone transfer standard.
Linearity Check
Since the Model 106 is inherently linear over several orders of magnitude, a
linearity check provides a test that the instrument is operating properly.
Instrument linearity can be checked by comparison to an ozone standard (see
Calibration Procedure – Calibration Curve) or by dilution of an ozone
measurement. To check the instrument linearity by dilution of an ozone
measurement, generate and measure a concentration of ozone near the upper
range of ozone monitor (80% of full scale is recommended). Additional ozone
concentrations should be generated by accurately diluting the ozone flow with
zero air and each concentration should be measured once the instrument
reaches a stable response. The accuracy of the linearity test relies on the
accuracy of the flow meters used to perform the dilution. The percent of non-
linearity is calculated from the formula:
