Teledyne 3020T - Manual (Page 53)

Trace Oxygen Analyzer Operation 4
4-17 Teledyne Analytical Instruments
Use the DOWN/UP
control to enter the upper value of the range (all
ranges begin at 0 ppm). Repeat for each range you want to set. ENTER to
accept the values and return to the Analysis Mode. (See note below.)
Note: The ranges must be increasing from low to high, for example,
if range 1 is set as 0–100 ppm and range 2 is set as 0–1,000
ppm, range 3 cannot be set as 0–500 ppm since it is lower than
range 2.
Ranges, alarms, and spans are always set in ppm units (over the entire
0-250,000 ppm range), even though all concentration-data outputs change
from ppm units to percent when the concentration is above 10,000 ppm.
After defining your analysis ranges, set
Mode– to either AUTO or one
of the fixed ranges, as described below.
4.10.2 Fixed Range Analysis
The autoranging mode of the instrument can be overridden, forcing the
analyzer DC outputs to stay in a single predetermined range.
To switch from autoranging to fixed range analysis, ENTER the
RANGE function by selecting RANGE from the MAIN MENU.
Use the DOWN/UP
control to move AUTO between the arrows.
Use the DOWN/UP
control to switch from AUTO to FX/LO, FX/MED,
or
FX/HI to set the instrument on the desired fixed range (low, medium, or
high).
L—100 M—1000
H—10000 Mode—FX/LO
or
L—100 M—1000
H—10000 Mode—FX/MED
or
L—100 M—1000
H—10000 Mode—FX/HI
ESCAPE to re-enter the ANALYZE screen using the fixed range.
NOTE:When performing analysis on a fixed range, if the oxygen
concentration rises above the upper limit, as established by
the setup, for that particular range, the output saturates at 1
V dc (or 20 mA). However, the digital readout and the RS-232