Teledyne 5000B - Near Infrared Photometer - Manual (Page 53)

Photometric Analyzer Operation /Control Unit 3
Part I 3-25 Teledyne Analytical Instruments
Select range
mode: MANUAL
If above screen displays, use the DÑ arrow keys to Select MANUAL,
and press Enter.
Select range to run
—> Ш1 Ш2 Ш3 CAL<—
Use the < > keys to select the range: 01, 02, 03, or CAL. Then press
Enter.
Fluid use: SO2
Range: Ø — 10 %
Use the < > keys to toggle between the Range: low-end field and the
Range: high-end field. Use the DÑ keys to change the values of the fields.
Press Escape to return to the previous screen to select or define another
range.
Press Enter to return the to the Analyze function.
3.6.2 Auto Screen
Autoranging will automatically set to the application that has at least
two ranges setup with the same fluides.
In the autoranging mode, the microprocessor automatically responds to
concentration changes by switching ranges for optimum readout sensitivity.
If the upper limit of the operating range is reached, the instrument automati-
cally shifts to the next higher range. If the concentration falls to below 85%
of full scale of the next lower range, the instrument switches to the lower
range. A corresponding shift in the DC concentration 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 contaminant 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 beyond the full-
scale setting until amplifier saturation is reached. Below amplifier saturation,
the overrange readings are accurate UNLESS the application uses lineariza-
tion over the selected range.