Siemens milltronics ILE-37, Instruction Manual

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.