Siemens Milltronics SF 500 - Page 53

7ML19985CN01 Milltronics SF 500 – INSTRUCTION MANUAL Page 47
mmmmm
Recalibration
Example:
A non-linearity in the ideal response exists in a solids flowmeter application with a
design rate of 200 t/h. Material tests are performed at 15, 30, 45, 60, and 75% of the design
rate. Perform a zero and a span calibration at 100% of the design rate, followed by
material tests and manual span adjust. The five material tests are performed at 30, 60, 90,
120, and 150 t/h, as indicated by the SF 500. The following data is tabulated. (This example
is exaggerated for emphasis.)
*calculation example: % compensation = 2.5 – 2.8 x 100
2.8
= - 10.7
SF 500 rate material test SF 500 total compensation*
t/h tonnes tonnes %
30 2.5 2.8 -10.7
60 5.0 4.5 11.1
90 7.5 7.9 -5.1
120 10.0 9.2 8.7
150 12.5 13.3 -6.0
0
5
10
15
20
25
30
0
12030
-10.7
-11.1
-5.1
8.7
-6.0
150 24060 18090 210
Weight = tonnes
actual weight per material test
totalized weight by SF 500
flowmeter response
linearized SF 500 response
internal response 100% - 150% of span
% compensation
span (100%)
rate t/h