User Guide

49
4. FREQUENTLY ASKED QUESTIONS & GLOSSARY
4.1. FAQ’S
The following list contains some of the most commonly asked questions relating to the M100E SO
2
Analyzer.
Q: Why is the ZERO or SPAN key not displayed during calibration?
A: The M100E disables certain these keys expected span or zero value entered by the users is too different
from the gas concentration actually measured value at the time. This is to prevent the accidental
recalibration of the analyzer to an out-of-range response curve.
EXAMPLE: The span set point is 400 ppb but gas concentration being measured is only 50 ppb.
For more information, refer to Section 12.4.4 and Section 12.4.5.
Q: Why doe
s the
ENTR key sometimes disappear on the Front Panel Display?
A: During certain types of adjustments or configuration operations, the ENTR key will disappear if you select
a setting that is nonsensical (such as trying to set the 24-hour clock to 25:00:00) or out of the allowable
range for that parameter (such as selecting an iDAS hold off period of more than 20 minutes).
Once you adjust the setting in question to an allowable value, the ENTR key will re-appear.
Q: How do I enter or change the value of my Span Gas?
A: Press the CONC key found under the CAL or CALS buttons of the main SAMPLE display menus to enter
the expected SO
2
span concentration.
Refer to Section 3.6.2.3 or for more information.
Q: Why doe
s the analyzer
not respond to span gas?
A: Section 12.4.4 has some possible answers to this
que
stion.
Q: Can I automate the calibration of my analyzer?
A: Any analyzer with zero/span valve or IZS option can be automatically calibrated using the instrument’s
AutoCal feature.
 However, the accuracy of the IZS option’s permeation tube is ±5%. While this may be acceptable for basic
calibration checks, the IZS option is not permitted as a calibration source in applications following US EPA
protocols.
 To achieve highest accuracy, it is recommended to use cylinders of calibrated span gases in combination
with a zero air source. Teledyne API offers a zero air generator Model 701 and a gas dilution calibrator
Model 700 for this purpose.
Q: What do I do if the concentration on the instrument's front panel display does not match the value recorded or
displayed on my data logger even if both instruments are properly calibrated?
A: This most commonly occurs for one of the following reasons:
 A difference in circuit ground between the analyzer and the data logger or a wiring problem;
 A scale problem with the input to the data logger.
The analog outputs of the M100E can be manually adjusted to compensate for either or both of these
effects, refer to 6.9.4.4;

The anal
og outputs are not calibrated, which can happen after a firmware upgrade.
Both the electronic scale and offset of the analog outputs can be adjusted (refer to Section 6.9.4.2).
Alternately, use the data logger itself as
the metering device during calibrations procedures.
04515F DCN6048