Model 306 Ozone Calibration Source Manual Rev. G-1
11
Both of the offset values,
Z_L
and
Z_H
, are in units of ppb. The Ozone Cal Source
is shipped with a NIST-traceable calibration. The calibration factors,
Z_L
,
S_L
,
Z_H
,
and
S_H
are
set in the instrument and recorded in the instrument’s calibration
document and birth certificate. However, you may choose to change the calibration
factors so that the instrument output agrees with your own ozone standard. You can
always return the instrument to its factory calibration if desired. To change the
calibration factor, place the cursor over the
Z_L
,
S_L
,
Z_H
,
or
S_H
and hold in the
select switch until the cursor blinks. You may now change the value of the calibration
factors by rotating the select switch. Increasing the slope (
S_L
) calibration factor
increases the ozone output concentration linearly for ozone values equal or less than
300 ppbv; i.e., for S=1.10, the ozone concentration produced will be 10% higher than
for S=1.00, and for S=0.95 it will be 5% lower. Likewise increasing the slope (
S_H
)
calibration factor increases the ozone output concentration linearly for ozone values
above 300ppbv. Once the desired value of
S_L
or
S_H
is selected, momentarily
press the select switch such that the cursor no longer blinks. The low and high offsets,
Z_L
and
Z_H,
are set in a similar fashion (in units of ppb). You may now exit the
Cal
submenu by selecting and clicking on
. See Section 8 for information on calibrating
your Model 306 Ozone Cal Source
TM
.
4.2.2 Program Submenu
Choosing the
Prg
submenu from the
Cfg
menu, allows one to define a program of
steps in ozone concentration. Choosing
Prg
results in the following submenu:
Prg Menu
Num Steps= x
Upon placing the cursor under the currently set value x and clicking, a blinking cursor
will appear. You may now rotate the select switch to obtain the number of steps, up to
10, you wish to have in your program. Clicking again will turn off the blinking cursor
and you may return the cursor to
to continue defining the program. After choosing
the number of steps, the following submenu will appear:
Prg Menu
Time/Step= x
You may now move the cursor to the currently set time/step value x, click to obtain a
blinking cursor and rotate the select switch to choose a step time in the range 1 to 60
minutes. To select the value, click to remove the blinking cursor, then use
to begin
defining the target concentrations of each of the steps. The following submenu will
now appear:
Select O3 Step
Step[1]= xxxx
where xxxx is the target ozone concentration in ppbv that is currently being used for
the first step of the program. You may now change the ozone concentration for the
first concentration step in the same way that the Time/step was changed. Executing
will bring up the following submenu and allow you to set the target concentration for
the next step:
Select O3 Step
Step[2]= xxxx
