GF Signet 8900 Multi-Parameter Controller - Manual (Page 42)

42 Signet 8900 Multi-Parameter
Custom point #10 3000 gal.
Custom point #1 0 gal.
Custom point #2 45 gal.
Custom point #3 118 gal.
Custom point #4
Custom point #5 250 gal.
Custom point #9 1300 gal.
Custom point #6 380 gal.
Custom point #7 700 gal.
Custom point #8 1000 gal.
160 gal.
Level and Volume conversion in custom shaped vessels
If you select Custom Shape in the Options menu, you can defi ne
from 2 to 20 Custom Points to establish the relationship of level to
volume in the vessel.
• Select Manual level Measurement mode to edit both level and
volume data (dry confi guration).
• Select Automatic level Measurement mode to accept the
sensor measurement of the Level, while you assign a
volumetric value to each custom point (wet confi guration).
• Enter from 2 to 20 custom points to link level and volume
values.
• The fi rst custom point must be the lowest fl uid level in the
vessel.
• Each successive point must be greater than the preceding
point.
• The last point must be equal to or greater than the highest
fl uid level in the vessel.
• A custom point should be located at all transition points in
the vessel shape (for example, at custom point #9, where the
shape changes from a cylinder to a cone).
• The more complex sections should be defi ned with more
points. Notice that the conical section of the illustration has
been defi ned by custom points 1 through 9.
• Simpler sections require fewer defi ning points. Note that the
cylinder requires only custom points 9 and 10.
Level, volume and mass calculations performed by the 8900
include:
Pressure to level conversion:
Level = P ÷ (SG • D
(water)
)
where P = Pressure
SG = Specifi c Gravity of fl uid
D
(water)
= Density of water
With pressure in psi: Level (meters) = (0.703069 • P / SG)
with pressure in bar: Level (meters) = 1.019715 • P / SG)
Mass conversion
m = D
(water)
• SG • V
where m = mass of fl uid
D
(water)
= Density of water = 1000 kg/m 3
SG = Specifi c Gravity of fl uid
V = Volume of fl uid (m 3 )
m (kg) = 1000 • SG • V
r
h
Length
A
Technical Reference for Level measurement
Volume calculations
Vertical cylinder: V = • d 2 • h/4
where d = diameter of cylinder
h = height of fl uid
Rectangular vessel: V = w • l • h
where w = width
l = length
h = height
Horizontal cylinder: V = A • L
where A = area of segment
L = Length of vessel
r = radius of vessel
h = height of segment
Custom vessel:
The 8900 performs linear interpolation between adjacent points.