Thermo Scientific TVA-1000B Instruction Manual - Geotech ...

Display Menus MI 611-185 – June 1996
Example: A TVA-1000B FID is calibrated with zero air and a 100 ppm Methane in air span
gas. The counts observed for the zero are 2895 and the counts observed for the span are
27395. The span sensitivity is thus 245 counts/ppm [(27395-2750)/100 ppm]. Since both of
these values (2895 zero counts and 245 detector sensitivity) are within the acceptable range,
the calibration is a good calibration. Examples of a bad calibration include unusually high
zero counts, or unusually low detector sensitivity. These problems can often be attributed to
poor calibration gases, contaminated sampling accessories, a faulty detector capsule, or failure
to follow the proper calibration procedure. For more information, consult the “Troubleshooting”
guide in this manual or contact TEI for assistance.
Defining the Span Gas Concentration(s)
NOTES:
1. The span gas concentration is the known concentration of the gas standards used to
calibrate your TVA. Methane in air is the recommended calibration standard for the
FID, and Isobutylene in air is the recommended calibration standard for the PID.
Other gases may be used if desired.
2. If your instrument is equipped with dual detectors, you may choose to calibrate the
PID and FID separately or together.
3. If your instrument is configured for multiple span points, be sure to set the concentration
for ALL span points.
1. From the CALIBRATION menu display, press 2=SpanConc. The upper display
(or two displays if the unit is a dual detector version) will display the concentration
value of your span gas (expressed as ppb, ppm, or %) as of the last calibration:
FID only PID only FID/PID
FID: 100 ppm
Span Gas Concent
Enter=New conc
PID: 100 ppm
PID: 100 ppm
FID: 100 ppm
Span Gas Concent
Enter=New conc Span Conc 1=Both
2=PID 3=FID
If the TVA-1000B is configured for multiple calibration points, the span gas concentration
values for Point #1 will be displayed. The Up and Down arrow keys can be used to scroll
through the span gas concentration values for other points:
FID only PID only FID/PID
FID: 100 ppm
Span Pt 1 (Up/Dn)
Enter=New conc
PID: 100 ppm
Span Pt 1 (Up/Dn)
Enter=New conc
PID: 100 ppm
FID: 100 ppm
Span Pt 1 (Up/Dn)
1=Both 2PID 3FID
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