[Fabian,Hirata-san,Kozu]
We changed the position of the secondary coil. The height of coil was 3.5mm from BF base plate.
We recalibrated SR2 BFLVDT roughly. The slope became 6261 from 6231. They are almost same.
The yoke was originally set to put the top of the PEEK former for the LVDT single coil at 6 mm above the baseplate (klog 4016), as shown in the 3D CAD. However the 3D CAD is wrong, and has the single coil above the center of the double coil by 2.5 mm when the keystone is at its nominal height of 65.5 mm. The correct height of the PEEK former is therefore 3.5 mm.
As pointed out before, because at the nominal height of the keystone the LVDT output was close to the end of the linear range, we decided to change the height of the secondary coil by 2 mm. The plot above shows the initial calibration curve and another curve we measured after moving the secondary coil. The new line has few data point compared to the original one. The change in slope is only 0.5%.
The final result reads as follows:
Output at keystone height 65.50 mm: -3425 counts.
Line: y = 6.262 counts/um – 422632 counts.
Linear range: ~ [63.00, 69.20] mm.