Teledyne GC-Pro/TCD - Gas Chromatograph - Manual (Page 35)

GC-Pro TCD Installation
Teledyne Analytical Instruments 21
0–1 VDC Range ID: 0.20 V = Low Range
0.5 V = Medium Range
0.80 V = High Range
4–20 mA DC % Range: Current increases linearly with
concentration, from 4 mA at 0
concentration to 20 mA at full scale.
(Full scale = 100% of programmable
range.)
4–20 mA dc Range ID: 6.8 mA = Range 1
12.0 mA = Range 2
16.8 mA = Range 3
Table 3-1: Analog Output Connections — Middle Connector
Pin Function
3 Channel 2, + 4-20 mA, floating
4 Channel 2, – 4-20 mA, floating
5 Channel 1, + 4-20 mA, floating
6 Channel 1, – 4-20 mA, floating
8 Channel 2, 0-1 VDC
23 Channel 2, 0-1 VDC, negative ground
24 Channel 1, 0-1 VDC
7 Channel 1, 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 auto
ranging 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 90-100% nitrogen then the output would be as
shown in Table 3-2.