Teledyne 3000TA-XLEU - Trace oxygen analyzer - Manual (Page 74)

Operation 3000TA-XL-EU
Teledyne Analytical Instruments 58
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 VDC (20 mA at the current output).
However, the digital readout and the RS-232 output of the
concentration 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
programmable.
Web enabled instruments can set and select ranges remotely using a
remote computer. See Section 5.4.
4.7.1 Setting the Analog Output Ranges
To set the ranges, enter the range function mode by pressing the
Range
button on the front panel.
L—1 M—10
H—100 Mode—AUTO
Use the ◄► arrow keys to blink the range to be set: low (L),
medium (M), or high (H).
Use the ▲▼ 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.