KROHNE UFM 800 EN - Manual (Page 4)

12/2000 Installation and operating instructions UFM 800 W / UFM 800 C 4
2.0 Sensor distance calculation
For calculating the sensor distance A it is necessary to know the internal diameter Di. For centering the sensor holders it is necessary to know the
wall thickness t and the external diameter D.
Drawing 1: Single beam flowmeter, principle dimensions for sensor positioning and GK-calculation A = Di + 11mm
Drawing 2: Double beam flowmeter, principle dimensions for sensor positioning and GK – calculation
In drawing 2:
α = 360° ⋅ ((Di ⋅ π/12 – 3,9) / (Di ⋅ π)
A = Di
⋅ 0,866 ⋅ √ 1 – tg
2
α + 7,8
1 + tg 2
α
The distance, measured over the outside of the pipe between the sensors 1 and 2 then equals 180 - 2
α ⋅ π ⋅ D
Ο
360
The distance, measured over the outside of the pipe between the sensors 1 and 4 then equals 2
α ⋅ π ⋅ D
Ο