2009 by ELTRA GmbH Germany – July 2009 – Service Manual Thermostep
Page 27
a.)
strong air movements or vibrations to the instrument from the support table
b.)
incorrect adjusted chimney of the balance
c.)
incorrect adjusted balance pedestal at the notch of the lower heating element
d.)
continuously purging over the balance
At a.) To minimize environmental influences site the Thermostep at a vibration-free, to
supply-air protected place. To minimize the influence of air movements keep the lower side
panels closed and use the function “
weighing with closed lid
” (see Operation Manual: Form –
Configuration
). Avoid knocks to the instrument during analysis, not to disturb weighing
procedure and to “produce” Junk-crucibles (see
2.6
).
At b.) Check if balance chimney is adjusted correctly (see
1.6
)!
At c.) Check if balance pedestal is adjusted correctly (see
1.6
)!
At d.) It is rarely possible that the unstability of the balance is due to an continuous purging at
the balance. At weighing the purging of the balance is switched off to avoid disturbance of the
balance pedestal by the purging gas.
A problem with the valve can cause unstability of the balance. Try to switch off purging
manually (see Operation Manual: Form –
Controller
) or to cut the external gas supply. If
there is a stabilization of the balance due to one of this points, the contimuous puriging is the
reason for the unstability. Please contact the manufacturer of the instrument!
2.5
Crucibles/Lids cannot be discharged/lifted
Error message:
“Can’t move lids up/down!”
“Can’t reach needed position!”
During analysis crucibles are moved to and from the balance pedestal. Afterwards the
caroussel is lifted up to site next crucible at the pedestal. For safety reasons a rotation of the
caroussel only takes place with lifted up caroussel, because lowered crucibles could damage
the pedestal during rotation. At this case the instrument reports unable to reach needed
position.
The following reasons can cause this problem:
a.)
insufficient pressure of compressed air
b.)
incorrect adjustment of the sensors
c.)
a defective valve at the valveblock
d.)
a defective cylinder
e.)
a defective pressure switch
At a.) To lift up/down the caroussels a gas pressure of compressed air of at least 4 bar (better
4,5 – 5 bar) is necessary. Check if gas pressure of compressed air is sufficient (see fig. 2.2)!
At b.) The lifting up and down of the carousels is controlled by sensors, that inspect the actual
status of the paricular carousel (
up
or
down
; see Operation Manual: Form -
Controller
).
Check if status is shown properly by software and correct position of sensors if necessary (see
1.2
).
At c.) Check if it is possible to lift up the caroussel manually (see Operation Manual: Form –
Contoller
). If this is not possible - despite sufficent pressure of compressed air – check the
corresponding valve (LHS; 4.valve at the valve block) (see
3.1
).
