User manual - DATA RECORDER SRD-99 and cooperating software
When 2-wires connection is used, the resistance of particular wires (Ra ÷ Rc)
NEEDN'T
BE
DIFFERENT
(should be as small as possible) When 3-wires connection is used, the
resistance of particular wires (Ra ÷ Rc)
MUST BE IDENTICAL
to enable proper compensation
of it's resistance. The resistance of particular wire
should not be greater than 20
Ω
.
a)
b)
Fig. 4.14. Connection of Pt100 sensors for channel no 1:
a) 3-wires circuit; b) 2-wires circuit;
The connection circuit should not be changed while unit is powered. Every change
of connection while the unit is powered causes measurement errors by several
seconds after change.
4.4.
MAINTENANCE
The unit does not have any internal replaceable or adjustable components available to
the user. Pay attention to the ambient temperature in the room where the unit is operating.
Excessively high temperatures cause faster ageing of the internal components and shorten the
fault-free time of the unit's operation.
In cases where the unit gets dirty do not clean with solvents. For cleaning use warm water with
small amount of detergent or in the case of more significant contamination ethyl or isopropyl
alcohol.
Using any other agents can cause permanent damage to the housing.
Product marked with this symbol should not be placed in municipal waste. Please
check local regulations for disposal of electronic products.
18
!
i
Pt100
Ra
Rb
Rc
24
26
25
Ra = Rb = Rc
Pt100
Ra
Rb
24 25 26
Ra, Rb as small as possible
n.c.
