Siemens FUG1010 IP65 NEMA 4X, Руководство по эксплуатации, Страница: 191 / 271

Appendix
A.6 Setting Thermal Coefficient and Modulus of Elasticity
FUG1010 IP65 NEMA 4X
190
Operating Instructions, 01/2013, A5E02951519-AC
The table may contain up to 32 pairs of these slope correction factors. Note that the Kc
factor, unlike these slope correction factors, is entered as a signed percent change in rate,
while these factors are simply rate multipliers. As points are entered, the point editor will
provide list access to the already entered points plus access to the [New Point] menu cell,
used to add a new point. The table may be created in its entirety and then activated by
selecting [Yes] in the [Table Active] menu cell. The entire table may be cleared by selecting
[Yes] in the [Clear Table] menu cell.
Note
Careless use of the calibration tables can have a detrimental impact on the measurement
performance of the flow meter.
Note
Take precautions before enabling these calibration tables. Although it is unlikely that all three
tables would ever be employed in a real installation, three tables are offered for maximum
user flexibility. Since the tables can be disabled without being destroyed, 2 or 3 optimization
strategies may be tested by this means in order to determine which approach is most
effective.
A.6 Setting Thermal Coefficient and Modulus of Elasticity
Introduction
This operating system includes routines that will compensate the measured raw flow rate for
dynamic changes in the pipe dimensions, caused by variations in line temperature and
pressure supplied to the flow meter. To account for variations in pipe material, two data entry
items (Thermal Expansion Coefficient and Modulus of Elasticity) are provided in the Pipe
Data menu screen (see sample menu screen below).
The equation used to automatically compute the change in pipe inside diameter is:
G G
α
7 7
3 3
(
Z
G
Where:
d
0
= inside diameter of pipe at STP
d
1
= inside diameter of pipe after temperature and pressure change
w = pipe wall thickness
T
0
and P
0
= Standard temperature and pressure
T
1
and P
1
= Operating temperature and pressure
α = Coefficient of Thermal Expansion of Pipe material
E = Modulus of Elasticity of pipe material