Teledyne 3010TB - Split architecture trace oxygen analyzer - Manual (Page 47)

Oxygen Analyzer Part I: Control Unit
Part I: 4-19
Teledyne Analytical Instruments
The Model 3010TB is set at the factory to default to autoranging. In this
mode, the microprocessor automatically responds to concentration changes
by switching ranges for optimum readout sensitivity. If the current range
limits are exceeded, the instrument will automatically shift to the next higher
range. If the concentration falls to below 85% of full scale of the next lower
range, the instrument will switch to that range. A corresponding shift in the
DC percent-of-range output, and in the range ID outputs, will be noticed.
The autoranging feature can be overridden so that analog output stays
on a fixed range regardless of the oxygen concentration detected. If the
concentration exceeds the upper limit of the range, the DC output will
saturate at 1 V dc (20 mA at the current output).
However, the digital readout and the RS-232 output of the concentra-
tion are unaffected by the fixed range. They continue to read accurately with
full precision. See Front Panel description in chapter 1.
The automatic air calibration range is always 0-25 % and is not pro-
grammable.
4.6.1 Setting the Analog Output Ranges
To set the ranges, enter the range function mode by pressing the
Range button on the front panel.
L—### M—####
H—##### Mode—AUTO
Use the < > arrow keys to blink the range to be set: low (L), medium
(M), or high (H).
Use the
Δ∇ arrow keys to enter the upper value of the range (all ranges
begin at 0 ppm). Repeat for each range you want to set. Press Enter to
accept the values and return to Analyze 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.