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

Display Menus MI 611-185 – June 1996
Scenario 2
If, for example, you want to measure several different compounds over wide concentration
ranges, it is best to use a single-point calibration and then enter response curves for each specific
compound (up to 9 response factors/curves can be entered into the analyzer).
Scenario 3
If, instead, you want to measure in direct readings (response factor = 1) for one specific compound
with maximum accuracy over a wide range of concentrations, perform a multipoint calibration
with the specific compound. Up to 9 span points (plus zero) can be entered for each
detector. The use of a response curve is thus unnecessary as the detector is already reading the
direct PPM for that specific compound.
CAUTION: If you use multipoint calibration or a gas other than methane or isobutylene
and then apply response factors/curves (that have been generated with reference
to a single point methane/isobutylene calibration), the resulting measurements will
probably be incorrect.
To provide the specified accuracy, the instrument must be calibrated at the beginning of each
workday. To reach the CALIBRATION menu from the MAIN MENU, choose 2 = Setup and
1 = Calib. When you reach the CALIBRATION menu, you will see the following selections:
Calibration MENU
1=Cfg 2=SpanConc
3=Zero 4=Span
5=RF 6=Backgnd
The steps involved in calibrating the TVA-1000B are as follows:
1. Configure the calibration variables (Cfg).
2. Define the span concentrations to be used (SpanConc).
3. Zero the instrument using either a zero gas or clean ambient air (Zero).
4. Calibrate the reference point(s) using known span gases. The TVA-1000B can be
configured for as many as nine (9) different span gas values (Span).
5. Optional: Set instrument response factors if necessary (RF).
6. Optional: Take background reading (Backgnd).
NOTE: Prior to performing calibration, the instrument must be on and warmed up
for approximately 30 minutes. The pump must be ON, the PID lamp must be ON,
and the FID must be ignited throughout the warm-up period.
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