8. GLOSSARY 
Amplitude (Magnitude)
The amount of force or the intensity of the vibration. 
AutoClamp 
Pneumatically-powered automatic wheel clamping device. 
Back Coning
When the wheel requires the cone to center the wheel on the balancer’s shaft from the 
backside, primarily due to the chamfer of the wheel. Also referred to as Back-Cone 
Mounting.
Backspacing
The distance measured from the mounting face to the back edge of the wheel. 
BDC
The abbreviation for bottom dead center also referred to as 6 o’clock. 
Bead seating 
The process of seating the tire to the rim bead seats. Bead seating preferably occurs just 
after the tire and rim have been assembled, but may gradually change and optimize over 
a longer period. If loaded with the GSP9720JLR load roller or driven, the position of the 
bead may optimize or always remain seated improperly, unless the tire is demounted, 
lubricated, and remounted. However, the load force and its’ relatively short duration will 
not necessarily solve defective mounting of the tire bead seat to the rim seat. 
Blinding and Rounding 
Blinding is a set amount if imbalance required before an indication of imbalance is 
displayed. Rounding sets the weight increments to specific amounts, such as tenths, or 
quarters, etc.  
Bolt Pattern Circle 
The diameter of an imaginary circle drawn through the center of each lughole, and 
virtually always on the same centerline as the hub bore of the wheel. 
CenteringCheck
Hunter feature that ensures the wheel is properly centered when mounted on the 
balancer. 
Couple Balance 
A procedure that corrects the imbalance in radial movement.  
Computerized Vibration Analyzer 
A device used to determine the frequency of the vibration by isolating the vibrations with 
the greatest magnitude. 
GSP9720JLR Wheel Balancer Operation Instructions  Glossary 
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