Teledyne 9110AH - Nitrogen oxides analyzer - Manual (Page 101)

TELEDYNE Model 9110AH NO
X
Analyzer Operator Manual, 01620, Rev. F
7-13
Use NO in nitrogen at 80% of calibration range 2% for routine calibration.
Example: Order 80 ppm NO in N2 if calibrating the 0-100 ppm range.
NOTE
It is important to note that if you are using blended calibration gasses,
other components of the blend can interfere with the NO concentration
value. This can affect calibration accuracy and linearity. See
Section 9.2.10 for additional details.
Zero Air:
Ultra Zero Grade Air, 99.999% pure
Nitrogen:
Ultra High purity Nitrogen, 99.999% pure
7.11.2 Calibration Frequency
Typically, the data acquisition system will perform a daily calibration. This consists of
switching valves to have calibration gas introduced at the sample probe and passing through the
entire sample induction system. The instrument or data acquisition system’s slope and offset
will be adjusted to produce the correct response of the system.
Once per quarter, the M9110AH should be calibrated using one of the procedures in Section 7.
Also a 3 point linearity check (zero, low span, high span) will be performed to confirm system
linearity.
It is important to note that when doing a linearity check, the calibration gasses have analysis
errors. For example if 2% standards are being used, the linearity could be theoretically be as
much as 4% in error, even if the instrument and sample induction system are “perfect”.
TELEDYNE recommends that EPA Protocol 1 ( 1%) gasses be used for linearity checks to
minimize non-linear responses due to analysis errors of the gas bottles.
7.11.3 Converter Efficiency
In many applications the NO
2
concentration is low enough (<5%) that converter efficiency
checks are not required. If your application requires an efficiency check, refer to 40 CFR, Part
60 Method 7E for the recommended procedure. Refer to Section 7.10 if automatic converter
efficiency compensation is required.