Endress+Hauser mycom CLM 121 - Page 34

Determination of temperature coefficient α
by measuring method (see fig. 6.5)
• The measuring solution is measured at two
temperatures T
1
and T
2
.
• Temperature T
1
should be as close as
possible to the reference temperature.
• For obvious reasons, temperature T
2
should
lie within the maximum operating
temperature range for the measuring
solution. (The difference between T
2
and T
1
must be at least 30 K).
The sequence required to determine the
temperature coefficient is shown in the
following table.
Note:
*)Error messages are issued if:
– temperature difference
T
2
– T
1
≤ 30 K
(error 85, see error list in
chapter 7.3)
– Conductivity value
κ
1
= 0 (Error 86)
– the temperature coefficient determined is
too small or too large (errors 87, 88)
Function
Matrix-
field /
command
Display
value
Instrument
display
Note
Matrix field selection V1 / H2 Conductivity at
temperature T
1
Temperature display →
→
Temperature T
1
→ key
functions as a
shift key
between
conductivity and
temperature
display
Store conductivity χ
1
and temperature T
1
value pair
E Conductivity
value at
temperature T
1
Stores values
only if
conductivity and
temperature
values are
stable
Heat measuring solution →
→
Temperature T
2
(T
2
at least
30 K above T
1
)
→ key
functions as a
shift key
between
conductivity and
temperature
display
Store conductivity χ
2
and temperature T
2
value pair
E Stores values
only if
conductivity and
temperature
values are
stable.
Repeat in case
of error
*)
Display of temperature
coefficient calculated by
the instrument
BE4LM151.CHP
mycom CLM 121/151 - CD/MM
6. Operation
33