Kistler-Morse KM Microcell Bolt-On - Manual (Page 32)

REMOVING A KNOWN QUANTITY
OF MATERIAL
See Figure 5-1.
1. Record the current live load.
2. Input HI Span: HI Span
= current live load.
3. Remove known quantity of material to the
vessel. Ensure all material has stopped
moving before proceeding.
4. Input LO Span: LO Span = HI Span - Removed
Weight.
Example
You are using Microcells™ to monitor a vessel. The vessel
contains 110,000 lb of material and can hold a maximum of
200,000 lb. You plan to remove 60,000 lb of material (which is
greater than 25% of 200,000 lb).
Following the Live Load Calibration procedure:
1. Current live load = 110,000 lb
2. HI Span = current live load = 110,000 lb
3. Remove 60,000 lb of material.
4. LO Span = HI Span - Removed Weight
= 110,000 lb - 60,000 lb
= 50,000 lb
MANUAL CALIBRATION
Note
The Kistler-Morse ® SVS-2000™ signal
processor performs a manual calibration
automatically with Quick Config.
See Figure 5-2.
1. Refer to the signal processor manual to
determine how to obtain the A/D converter
sensitivity, expressed in Counts/mV. Record
this value.
2. Record the Microcell™ sensitivity (S).
Sensitivity for Microcells™ on legs and beams
are shown in Table 5-1.
3. Refer to the Application Data Form for the
vessel (contact Kistler-Morse ® for an additional
copy if needed). Record the maximum live
load and the stress.
4. Record the current live load in the vessel.
5. Calculate the Manual Calibration values:
Scale Factor Weight = maximum live load
Scale Factor Counts = S * Counts/mV * Stress
Zero_Cal = current live load
6. Refer to the signal processor manual to input
the calibration values.
Example 1. Microcells™ on Vertical Legs.
You are using 3” Microcells™ in rosette arrays on vertical
column legs. The vessel has four W10x39 carbon steel legs
and no braces. The vessel currently contains 50,000 lb of
material and can hold a maximum of 200,000 lb.
Following the procedure:
1. Counts/mV = 699.05 (from signal processor)
2. S = 0.045 mV/psi (From Table 5-1, for legs with rosette
array)
3. From the Application Data Form, the maximum live load
is 200,000 lb. The stress is 4348 psi.
4. Current live load = 50,000 lb
5. Calculate the values for the calibration:
Scale Factor Weight = Maximum live load = 200,000 lb
Scale Factor Counts = S * Counts/mV * Stress
= 0.045 mV/psi * 699.05 Counts/mV * 4348 psi
= 136,776 Counts
Zero_Cal = current live load = 50,000 lb
Example 2. Microcells™ on Beams.
You are using 3” Microcells™ on beams. The vessel has four
W10x39 carbon steel horizontal beams and four W10 x 39
carbon steel diagonal beams. The Microcells™ are on the
horizontal beams only. The vessel currently contains
50,000 lb of material and can hold a maximum of 150,000 lb.
Following the procedure:
1. Counts/mV = 699.05 (from signal processor)
2. S = 0.070 mV/psi (From Table 5-1, for beams)
3. From the Application Data Form, the maximum live load
is 150,000 lb. The stress is 5929 psi.
4. Current live load = 50,000 lb
5. Calculate the values for the calibration:
Scale Factor Weight = Maximum live load = 150,000 lb
Scale Factor Counts = S * Counts/mV * Stress
= 0.070 mV/psi * 699.05 Counts/mV * 5929 psi
= 290,127 Counts
Zero_Cal = current live load = 50,000 lb
Figure 5-2. Manual Calibration Line.
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