Teledyne N500, Руководство пользователя, Страница: 80 / 99

78 Teledyne API N500 CAPS NO
X
Analyzer with NumaView™ Software
089770000 Rev 05
I
NABILITY TO
S
PAN
- D
EACTIVATED
SPAN B
UTTON
In general, the analyzer will deactivate certain buttons whenever the actual value of a
parameter is outside of the expected range for that parameter. If the Span is grayed out,
the actual concentration must be outside of the range of the expected span gas
concentration, which can have several causes.
1. Verify that the expected concentration is set properly to the actual span gas
concentration in the CONC sub-menu.
2. Confirm that the NO
2
span gas source is accurate.
• This can be done by comparing the source with another calibrated analyzer.
3. Check for leaks in the pneumatic systems as described in Section 5.6.5.
•
Leaks can dilute the span gas and, hence, the concentration that the analyzer
measures may fall short of the expected concentration defined in the CONC
sub-menu.
I
NABILITY TO
Z
ERO
- D
EACTIVATED
ZERO B
UTTON
In general, the analyzer will deactivate certain buttons whenever the actual value of a
parameter is outside of the expected range for that parameter. If the Zero button is grayed
out, the actual gas concentration must be significantly different from the actual zero point
(as per last calibration), which may be for any of several reasons.
1. Confirm that there is a good source of zero air.
2. Check to ensure that there is no ambient air leaking into zero air line.
3. Check for leaks in the pneumatic systems as described in Section 5.6.5.
N
ON
-L
INEAR
R
ESPONSE
The analyzer was factory calibrated to a high level of NO
2
and should be linear to within
1% of full scale. Common causes for non-linearity are:
•
Leaks in the pneumatic system:
•
Leaks can add ambient air, zero air or span gas to the current sample gas
stream, which may be changing in concentrations as the linearity test is
performed.
• Check for leaks as described in Section 5.6.5.
•
The calibration device is in error:
• Check flow rates and concentrations, particularly when using low
concentrations.
• If a mass flow calibrator is used and the flow is less than 10% of the full scale
flow on either flow controller, you may need to purchase lower concentration
standards.
• The standard gases may be mislabeled as to type or concentration.
•
Labeled concentrations may be outside the certified tolerance.
•
The sample delivery system may be contaminated.
• Check for dirt in the sample lines or reaction cell.
• Dilution air contains sample or span gas.