BERTHOLD TECHNOLOGIES LB 444 - Calculation of Square Temperature Coefficient

04/03 347 LB 444
52
7.6 Calculation of Square Temperature Coefficient
If significant temperature variations are likely to occur in the product (approx. > ± 20°C),
it is advisable to enter the square temperature coefficient as well.
Calculation:
a) Calculate TC
1
(see above)
b) With TC
1
calculate nominal value ρ
2
'
at higher temperature
ρ
2
'
= ρ
1
+ (ϑ
1
- ϑ
2
) *·TC
1
c) Take actual density value ρ
2
from table
d) Calculate TC
2
:
()
-
- '
= TC
2
21
22
2
ϑϑ
ρ
ρ
e) Enter calculated value TC
2
as temperature coefficient TC2.
Example:
Ethanol, concentration 30 %, reading in g/cm
3
, relative to 10°C.
1
st
temperature coefficient in range 10 - 20° C:
3
1
10*59.0
2010
9540.09599.0
−
=
−
−
−=TC
Input value TC1: 5.9e-04
Calculate nominal value ρ
2
' of density calculated using the calculated TC
1
at 100° C:
ρ
2
= 0.9599 + (10 - 100) * 0.59 *10
-3
= 0.9068
ρ
2
(table value) = 0.8936
6
2
2
10*2962.1
)10010(
8963.09068.0
−
=
−
−
=TC
Input value TC2: 1.2962e-06