For optimized performance of single point measurements with the OFV-552 Differential Sensor Head. The OFV-153 Adjustable Reference Head terminates the reference fiber when working in single-point mode. A slider allows adjustment of the optical path length in the reference fiber, thereby providing means to set the system to the visibility maximum.

Note: The OFV-153 Adjustable Reference Head requires the OFV-102 Fiber Head.