Teledyne 7300A Operating Instructions Manual page 17

Infrared Gas Analyzer
4–20 mA dc % Range: Current rises linearly with concentration, from 4
4–20 mA dc Range ID: 8 mA = Range 1, 12 mA = Range 2, 16 mA =
The analog output signal has a voltage which depends on gas concen-
tration relative to the full scale of the 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 0–10 % carbon monoxide, then the output would be as shown in
Table 2-3.
Table 2-3: Analog Concentration Output—Example
mA at 0 concentration to 20 mA at full scale. (Full
scale = 100% of programmable range.)
Range 3, 20 mA = Range 4.
Table 2-2: Analog Output Connections
Pin Function
3 + Range ID, 4-20 mA, floating
4 – Range ID, 4-20 mA, floating
5 + % Range, 4-20 mA, floating
6 – % Range, 4-20 mA, floating
8 + Range ID, 0-1 V dc
23 – Range ID, 0-1 V dc, negative ground
24 + % Range, 0-1 V dc
7 – % Range, 0-1 V dc, negative ground
Examples:
Percent Voltage Signal
CO Output (V dc)
0 0.0
1 0.1
2 0.2
3 0.3
4 0.4
5 0.5
Teledyne Analytical Instruments
Installation 2
Current Signal
Output (mA dc)
4.0
5.6
7.2
8.8
10.4
12.0
2-5