Model 408 NO Calibration Source Manual Rev. D-3
12
4.6.2 Fm2 (output flow cal factor)
This is the cal factor for the output air flow of the 408 NO Calibration Source
. If the
user has access to a reliable flow meter and finds a difference in actual flow versus
the flow readout, this can be adjusted as needed. To determine the flow cal factor, set
Fm2 =1.00 then use: (Actual vol. flow/readout vol. flow)=Fm2 cal factor and adjust this
cal factor as needed.
4.6.3 NO (NO cal factors):
Selecting this option takes the user to the 408 NO cal factors and the LCD will display,
NO Cal Menu
Cal_l Cal_h
The 408 NO Calibration Source
makes use of 2 sets of calibration factors both with
Z (offset) and S (slope or sensitivity) for different selected NO concentrations. Cal_l
menu contains the low concentrations cal factors and uses these factors when
selecting concentrations of 20-250 ppb. Cal_h is a different set of cal factors used
when selecting concentrations 251-1000 ppb. Every 408 NO Calibration Source
is
shipped with a NIST-traceable calibration. Both Cal_l and Cal_h calibration factors (
Z
and
S
)
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 nitric oxide standard. You can always
return the instrument to its factory calibration if desired. To change the calibration
factor, place the cursor over the digit (
x
) you wish to change and hold in the Select
Switch until the cursor blinks. You may now change the value of the digit by rotating
the Select Switch. Once the desired value of a digit is selected, momentarily press
the Select Switch such that the cursor no longer blinks. You may now rotate the
Select Switch to choose another digit to change. The
Z
parameter is a “zero” or
“offset”, and the
S
parame
ter is a “gain” (“slope” or “sensitivity”) factor. Increasing the
Z
parameter increases the concentration of NO produced in an additive way. For
example, changing
Z
from 1.3 to 2.4 will cause the NO output to increase by 1.1 ppb.
Increasing the
S
parameter increases the NO output concentration linearly; i.e., for
S=1.10, the NO concentration produced will be 10% higher than for S=1.00, and for
S=0.95 it will be 5% lower. Once the desired value of a digit is selected, momentarily
press the Select Switch such that the cursor no longer blinks. You may now exit the
Cal
submenu by selecting and clicking on
.
4.7
Error Codes
Error codes are displayed if any of the four key parameters (temperature, air flow rate,
N
2
O flow rate, and lamp intensity) are out of range as follows:
Code
Error
1
N
2
O flow out of range (40
– 80 mL/min)
2
Air flow rate out of range (3.3
– 3.8 L/min)
