2009 by ELTRA GmbH Germany – July 2009 – Service Manual Thermostep
Page 11
The voltages were measured with a voltage measuring device at the points TP1 (ground) and
TP2, TP3 respectivly TP4 at the board (see Fig. 1.6). TP2 should show about 24V and TP3
should show about 12 V. TP4 is the supply voltage of the thermocouple and should show
about 5V. (This voltage is not shown at form
Status
!) This voltage is adjustable at the
potentiometer
R9
with a small screw driver.
Fig. 1.6: RHS - Main bord (voltage measuring points marked by red arrow)
1.8
Measurement of reference temperature
Required tools:
voltage measuring device
The reference temperature is used as an alignment of the thermocouple and is ascertained via
the adjacent voltage at TP6.
Use the voltage measuring device at TP1 (ground) and TP6 and read the determined voltage.
This voltage equates a temperature, that you can check at the enclosed index and indicates the
proper functionality of the thermocouple.
1.9
Regulation of gaspressure, flow
During an analysis it is possible to create a Nitorgen- or Oxygen-atmosphere at the furnace.
For this the selected gas is fed through feed pipes at the upper heating element. The gas
pressure can be read at the pressure manometer at the frontside of the analyser and should be
about 1,5 bar. The gasflow can be read at the flowmeter and should be about 400 l/h. Before
you start to adjust the gaspressure make sure that the gas bottle pressure of your Nitorgen and
Oxygen is sufficient!
The adjustment of the gaspressure is done by the according pressure controller at the LHS
(Please note: TGAs with two cylinders for lifting the cover have the gaspressure regulators at
the RHS). The front pressure controller regulates the Oxygen- and the rear pressure controller
regulates the Nitrogen pressure.
a.)
For examination of the gaspressure activate the particular gas at form “
Controller”
and
check the pressure at the pressure gauge.
b.)
To adjust the gas pressure extract the pressure controller and turn it until the required
pressure is reached.
