Teledyne 4020 - Hydrocarbon analyzer - Manual (Page 35)

Total Hydrocarbon Analyzer Installation
Teledyne Analytical Instruments 19
23 – Range ID, 0-1 VDC, negative ground
24 + % Range, 0-1 VDC
7 – % Range, 0-1 VDC, negative ground
Examples:
The analog output signal has a voltage which depends on gas
concentration 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 ppm CH
4
, then the output would be as shown in
Table 3-2.
To provide an indication of the range, the Range ID analog outputs
are used. They generate a steady preset voltage (or current when using
the current outputs) to represent a particular range. Table 3-3 gives the
range ID output for each analysis range.
Table 3-2: Analog Concentration Output—Example
ppm Voltage Signal Current Signal
CH4 Output (VDC) Output (mA DC)
0 0.0 4.0
1 0.1 5.6
2 0.2 7.2
3 0.3 8.8
4 0.4 10.4
5 0.5 12.0
6 0.6 13.6
7 0.7 15.2
8 0.8 16.8
9 0.9 18.4
10 1.0 20.0