Emerson 8800A, Product Manual

Page: 59 / 160

3-11
Operation
Mating Pipe ID
(Inside Diameter)
The Pipe ID (Inside Diameter) of the pipe adjacent to the flow meter
can cause entrance effects that may alter flowmeter readings. You must
specify the exact inside diameter of the pipe to correct for these effects.
Enter the appropriate value for this variable.
Pipe ID values for schedule 10, 40, and 80 piping are given in Table 3-1.
If the piping in your application is not one of these, you may need to
contact the manufacturer for exact Pipe ID.
f
Damping
Damping changes the response time of the flowmeter to smooth
variations in output readings caused by rapid changes in input.
Damping is applied to the Analog Output, Process Variable, and
Percent Range. This will not affect the Pulse Output or Total.
NOTE
If the vortex shedding frequency is slower than the damped value
selected, no damping is applied.
The default damping value is 2.0 seconds. This can be reset to any
value between 0.2 and 255 seconds.
Determine the appropriate damping setting based on the necessary
response time, signal stability, and other requirements of the loop
dynamics in your system.
HART Comm. 1, 3, 6
Table 3-1. Pipe IDs for Schedule 10, 40, and 80 Piping
Pipe Size
Inches (mm)
Schedule 10
Inches (mm) Schedule 40
Inches (mm) Schedule 80
Inches (mm)
½ (15) 0.674 (17.12) 0.622 (15.80) 0.546 (13.87)
1 (25) 1.097 (27.86) 1.049 (26.64) 0.957 (24.31)
1½ (40) 1.682 (42.72) 1.610 (40.89) 1.500 (38.10)
2 (50) 2.157 (54.79) 2.067 (52.50) 1.939 (49.25)
3 (80) 3.260 (82.80) 3.068 (77.93) 2.900 (73.66)
4 (100) 4.260 (108.2) 4.026 (102.3) 3.826 (97.18)
6 (150) 6.357 (161.5) 6.065 (154.1) 5.716 (145.2)
8 (200) 8.329 (211.6) 7.981 (202.7) 7.625 (193.7)
10 (250) 10.420 (264.67) 10.020 (254.51) 9.562 (242.87)
12 (300) 12.390 (314.71) 12.000 (304.80) 11.374 (288.90)
HART Comm. 1, 3, 7