Soft dB OBSI Software User Guide - Manual (Page 8)

4
General OBSI Setup - Probe position
The current OBSI standard specifies use of an ASTM F2493 Standard Reference Test Tire (SRTT)
(P225/60R16) available from Michelin. A purchasing procedure is detailed in appendix.
Mic A Mic B
5/8” - 16 mm
3” - 76 mm
4” - 102 mm
Leading and trailing
probes must be placed
4.125” from the center
of the wheel hub