ELTRA CS-2000, Service Manual

Page: 48 / 160

Faults
48
2. Too high noise
One more reason could be exceptionally high noise. The base lines and the level of their noise
can be seen on the screen when clicking on the base lines icon (with three waves).
Reasons for noise are:
–
The infrared detector,
replace, see chapter “
IR paths cleaning and replacing
” and
“
Infrared base lines
”.
–
The pre-amplifier, replace it, see
chapter “
Infrared electronics
”.
–
A fault on the IR circuit board IRC-1, replace it, see
chapter “
Infrared electronics
”..
–
The IR source is defective, see
chapter “
The analysis takes too long
” and “
IR sources
”.
–
The microcontroller board.
–
The power supply fluctuates, see
chapter “
Infrared electronics
”.
In case of a module (rack) of more than one IR-cell, mostly only one of the base lines has too
high noise while the others have noise in normal range. In order to localize whether the noise is
created by the sensor, preamplifier or the corresponding section of the IRC board, interchange
the preamp connector of the noisy range with another one on the IRC board. If the noise moves
to the other range on the PC screen (base line color), this means that the noise is created by
the sensor or preamplifier.
In this case replace first the sensor as the more probable reason and if this doesn't help,
replace the preamplifier.
NOTE
Don't forget to connect the interchanged connectors to the original position again.
–
If the noise is created by the IRC board, change it.
3. Too high drift
Another reason for report of instability is a too high drift of at least one cell, so that the signal of
one cell reaches the end of the set window (mV).
A drift can be due to temperature changes of the IR cell. It happens when the cell temperature
is still not stable after switching on the power. When switching on the power after long break so
that the cell is cold, allow the cell at least 30 minutes to stabilize the temperature. This has to be
taken into consideration when checking the base line stability.
When starting the oxygen flow (power switch on position 3), the cell takes about 5 minutes to
stabilize when restarting the oxygen flow after long time without flow (but with uninterrupted
power).
Pos : 3. 34 /0025 Übersc hrift en/ELTRA 1.1 Übersc hrift en/11 C ombusti on t ube breaks freq uentl y @ 6\ mod_1368628553320_9. doc x @ 40424 @ 2 @ 1
3.17 Combustion tube breaks frequently
Pos : 3. 35 /0010 ELTR A/ 0015 s ervic e_ins truc tions/C S-2000_s er vice/ 05Faults _C S-2000/ 0605 M odul C ombusti on t ube ser vic e lif e t oo s hor t @ 9\ mod_1425540856869_9. doc x @ 74333 @ @ 1
Induction furnace:
–
The sample weight or the weight of the accelerator is too high.
– Don’t use copper as accelerator.
Resistance furnace:
–
The furnace temperature is too high. Usual operation temperature are 1350°C.The higher
the temperature the shorter the service expectancy of the ceramic tube.
–
The faster the furnace heats up, the higher the stress for the combustion tube. A
compromise is to lower the current limit of the heating up current.
See chapter
“
Resistance furnace
”. in this manual