Model 408 NO Calibration Source Manual Rev. D-3
9
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 begin 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. (NOTE: the 408 will take a few minutes to get up to concentrations and it is
recommended to run step functions for at least 8 minutes for best results.) 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 NO Step
Step[1]= xxxx
Where xxxx is the target NO concentration in ppb that is currently being used for the
first step of the program. You may now change the NO 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 NO Step
Step[2]= xxxx
This process is repeated until the target concentrations are set for all of the steps in
your program.
This program resides in memory until the next time you choose to change it.
Choosing
Run
executes the program of concentration steps you have stored in
memory (under
Adv/Cfg/Prg
). The target concentrations are displayed as the
instrument steps through the program. For example, the first display might read
Step[1]=100 ppb
delT=0.2
▌▌▌▌▌
if you have chosen 100 ppb as the target concentration for your first step and the
photolysis chamber is higher than the target value by 0.2
°
C. The five solid bars
indicate that the cell temperature, N
2
O flow rate, total flow rate and lamp intensity are
within range for accurate output of the selected NO concentration. If any critical
parameter or combination of parameters is out of range, an error code will appear in
place of the bars.
