Siemens Milltronics L-300, Инструкция по эксплуатации

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Page 6 Milltronics L-300 – INSTRUCTION MANUAL 7ML19985EQ01
Dual Load Cell Balance
Verify the load cell signal balance before the initial start up of the flowmeter. Repeat this
procedure when one or both load cells are replaced.
Remove the cover plate on the back of the flowmeter and identify load cell “A” and load
cell “B”. When doing the load cell balance, as described in the integrator manual,
suspend a test weight from calibration position “B” and “A” as required using the
calibration pulley.
Follow the balancing instructions provided in the integrator instruction manual.
Calibration
Calibration weights are normally supplied with the Milltronics L-300. The following is the
basis for determining the weight(s) value in t/h for initial calibration. The value of the
calibration weight will be different after material tests have been completed and the
calibration factored to the same.
Program and calibrate the flowmeter/integrator system as described in the integrator
manual. However, before a system can be calibrated, a calibration weight should be
selected. The mass of this weight is based on a nominal value of 45 g per t/h
1
and should
be selected for 60 to 80% of the design flowrate.
Example:
Design rate = 300 t/h
Test rate to equal 70% of design rate
Test weight value = 300 t/h x 70% = 210 t/h
Test weight mass = 210 t/h x 45 g per t/h = 9.45kg
With the calibration weight selected, the integrator can be programmed and the system
calibrated as described in the integrator manual. For span calibration purposes, the
calibration weight should normally be applied at the center position.
After calibration, remove the calibration pulley and replace the cover plate. If possible,
perform material tests after calibration to verify the accuracy of the span calibration.
Material Tests
After installation, perform a material test using a known amount. Run the material
through the flowmeter and check the flowmeter integrator totalized value against the
known amount.
Use the manual span adjustment feature in the flowmeter integrator to make
adjustments for greatest accuracy.
1.
Free flowing, high velocity, granular products such as wheat and corn will pro-
duce higher g per t/h forces.