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

MI 611-185 – June 1996
Display Menus
2. To change a span gas concentration value, choose the detector(s) of interest if using
a dual detector analyzer, or press ENTER if using a single detector analyzer. The
following display will appear:
FID only PID only FID/PID
Enter Span Conc:
FID: 000000 ppm
Up/Dn=Next unit
Enter=Accept
Enter Span Conc:
PID: 000000 ppm
Up/Dn=Next unit
Enter=Accept
Enter Span Conc:
P&F: 000000 ppm
Up/Dn=Next unit
Enter=Accept
Use the up and down arrow keys to select the measurement units (%, ppm, or ppb) and the
decimal point position. There are 5 selections to choose from:
Range Display Units
5 DD.DD %
4 DDDDDD ppm
3 DDDD.D ppm
2 DDD.DD ppm
1 DDDDDD ppb
The range of the instrument is determined by your selection of measurement units and decimal
point placement. In the run mode, the instrument will auto range upward only to select
the optimum range for displaying measurement information. For example, if you entered a
value in Range 3 and the measured value changes to a high value, the instrument will automatically
switch to range 4. If it increases further, it will switch to Range 5. Auto-ranging will
not switch ranges beyond the span gas range in the downward direction.
After you have selected the measurement units and decimal point placement, use the keypad
to enter the concentration value. Press ENTER to accept this value and store it in the TVA’s
memory.
3. If your TVA-1000B is a dual detector analyzer, you may repeat the procedure for
the second detector. If your TVA-1000B is configured for more than one span
point, you may use the Up/Dn arrow keys to select the next span point and repeat
the procedure.
4. When the last gas concentration value has been entered, you can return to the
CALIBRATION menu, by pressing the EXIT key.
Defining the Response Factor
Although the FID and PID are calibrated with span gases of known concentration (usually
Methane and Isobutylene, respectively), both detectors respond to many different compounds
with differing levels of sensitivity. In order to adjust the analyzer reading from “ppm of
Methane” or “ppm of Isobutylene” to ppm of the compound of interest, a correction factor
must be applied to the reading. This correction factor is also known as a Response Factor. You
can choose from up to nine (9) user-defined response factors, or use the default response factor
of 1.00. Each response factor can be assigned a 9-character alphanumeric name.
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