Zero adjustment
If an autozero is triggered manually or by a time pro-
gram, the microcontroller compensates the bridge off-
set. To do this, it determines an appropriate number of
pulses per unit in time. It passes these pulses on to the
bridge via field-effect transistors. It switches the two
relays according to the required polarity.
Polarity
Peaks can be positive or negative depending on the car-
rier gas and the components. The polarity of the signal
can be switched over in the detector electronics by the
software. To find out how this is carried out, refer to
Register 5: Detectors: Changing the polarity.
Status
The TCD signals Alarm if the bridge current monitor-
ing function switches off the bridge current.
Connection of detector
Refer to the connection diagram below.
TCD
1
2
3
4
5
6
7
8
9
10
TCD amplifier
X8
red
white
black
blue
Measurement
Meas.
Reference
+ I
B
- I
B
+ U
M
- U
M
Reference
Bridge current +
Bridge current -
Carrier gas monitoring
Input signal -
Input signal +
+ 24 V
Classified overtemperature switch
:
60
61
62
63
64
65
:
:
74
Terminal board
XK1
GND
Carrier gas
alarm
Detector electronics
9DETEKT.CHP, Stand Dezember 22, 1999
7
To Next Page
Loading...
