Siemens milltronics ILE-37, Инструкция по эксплуатации

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7ML19985CW01 Milltronics ILE-37 – INSTRUCTION MANUAL Page 13
Range Springs
The range spring establishes the range of sensing head moving beam travel for a given
range of material flow. This spring is installed in the flowmeter sensing head at the
factory. The spring is selected according to the specified design rate of the application.
For best operation, the range spring should provide 0.75 to 2.4 mm (0.030 to 0.094") of
moving beam travel from the static zero to the design rate operation position. The moving
beam travel may be inferred from the value of the LVDT output, as measured between the
LVDT green and yellow wires (or yellow and white wires in the case of a hazardous-rated
LVDT unit).
With the 2.5 V AC, 2.9 kHz LVDT excitation supplied:
• 0.75 mm of moving beam movement = 0.188 V AC output
• 2.40 mm of moving beam movement = 0.600 V AC output
Should the design rate of the flowmeter application change, it may be necessary to select
and install another range spring to obtain the optimum moving beam travel (LVDT output)
range.
Range Spring Removal
1. Loosen the range spring locknut.
2. Remove the range spring mounting bolt and three flange mounting bolts.
3. Remove the range spring from the range spring assembly.
Range Spring Replacement
1. Install the new range spring in the range spring assembly.
2. Mount the range spring assembly by the three flange mounting bolts.
3. With the moving beam in the static zero position, thread the range spring until the
base just touches the static beam and then turn one complete revolution more.
4. Install the range spring mounting bolt and tighten the range spring locknut.
Flowmeter Recalibration
After you have removed and replaced the range spring, recalibrate the flowmeter and
integrator. (See the Integrator manual, CALIBRATION section, for details.)
1. Perform the LVDT output zero procedure.
2. Perform an integrator zero and span calibration.
3. Perform a span Adjust and factoring as required.