Teledyne 4020 – Hydrocarbon analyzer (special version for automatic background gas switching) - Manual (Page 65)

Total Hydrocarbon Analyzer Operation
Teledyne Analytical Instruments 47
4.6.11 Zero and Span Functions
The ZERO and SPAN functions are used to calibrate the analyzer.
These functions can be performed either manually or automatically (if
equipped with the autocal option). The ZERO and SPAN are separate
functions but operate similarly. Hence, the description that follows
refers to the ZERO function but the same procedure is used for SPAN.
The analyzer is calibrated using zero and span gases as described in
Section 4.1. This section assumes that these gases have been properly
connected and the lines checked for leaks.
Note: You must zero and span calibrate the instrument with each
background gas (O
2
or N
2
) you intend on using.
To initiate a zero (span) calibration, first inform the instrument
which background gas is being used:
<▲▼> From the MAIN MENU, scroll down to the Background
Gas function.
<Enter> Press to activate the Background Gas function.
<▲▼> Use the UP or DOWN key to toggle between O2, N2, and
AUTO until the correct background gas is displayed.
<Enter> Press again to inform the instrument which gas
is being used for the background gas.
The parameters for the calibration that follows will be stored in
memory for the background gas selected.
<▲▼> From the MAIN MENU, scroll down to the ZERO
(SPAN) function.
<Enter> Press to activate the ZERO (SPAN) function.
The next screen will prompt you to select either manual
or automatic Zero calibration.
Manual Zero (Span)
If you select manual zero (span), the next screen will allow you to
enter the concentration in ppm hydrocarbon (methane equivalent) of
your zero(span) gas.
Note: Make sure that the proper calibration gas is flowing into the
analyzer before initiating this function. Depending on your