Trace Oxygen Analyzer Installation 3
3-5Teledyne Analytical Instruments
Figure 3-5: Analog Output Connections
The outputs are:
0–1 V dc % of Range: Voltage rises linearly with increasing oxygen, from
0 V at 0 ppm to 1 V at full scale ppm. (Full scale =
100% of programmable range.)
0–1 V dc Range ID: 0.25 V = Low Range, 0.5 V = Medium Range,
0.75 V = High Range, 1 V = Air Cal Range.
4–20 mA dc % Range: Current increases linearly with increasing oxygen,
from 4 mA at 0 ppm to 20 mA at full scale ppm.
(Full scale = 100% of programmable range.)
4–20 mA dc Range ID: 8 mA = Low Range, 12 mA = Medium Range, 16
mA = High Range, 20 mA = Air Cal Range.
Examples:
The analog output signal has a voltage which depends on the oxygen
concentration AND the currently activated analysis range. To relate the
signal output to the actual concentration, it is necessary to know what range
the instrument is currently on, especially when the analyzer is in the
autoranging mode.
The signal output for concentration is linear over the currently selected
analysis range. For example, if the analyzer is set on a range that was defined
as 0–100 ppm O2, then the output would be as shown in Table 3-1.