GasCheck
Operating Manual V2.4
6
+15V
source drive
signal processor
P3
P4
output
P2
P1
+15V
78L05
100nF
(+5V)
0-1V
1kR
Figure 3.5
Equivalent circuit for GasCheck sensor
There is a 1k
resistor in series with the output. This is included to protect the
output from damage in the event of it being shorted by the supply rails. The
output may be connected to external high impedance circuits (such as non -
inverting, op-amp based amplifiers) or low impedance circuits (such as
inverting, op-amp based amplifiers). If connected to a low impedance circuit,
the output resistance should be included in any gain calculations.
Output resistance = 1 k
+ 1% (50 ppm /
C temperature coefficient)
3.4
Electrical Connection - for GasCheck with linearisation board
Electrical connection is normally made at terminal block TB1 on the sensor.
The nominal 24V DC supply should be connected between the terminals
marked
0V
and
+24V
. The analogue output (current or voltage) is available at
the terminals marked
+
and
-
.
The
-
terminal is connected to the 0V terminal thereby referencing the
analogue output to the negative power rail.
