VeEX OTDR Series User Manual page 37

• Ultra-Physical Contact (UPC) - The UPC style ferrule has the shape of the PC style,
except they are polished with several grades of polishing film that allows for an ultra-
smooth surface. The main difference between UPC and PC is that the former has lower
return loss.
• Angled Physical Contact (APC) - The APC style produces the lowest return loss when
compared to other styles. The ferrule is polished to an angle of 8 degrees. The angle is
calculated so that it is less than the critical angle, which ensures light is not propagated
back along the fiber.
Connector Polish and Performance
Typical Return loss values are:
• Polished Connector ~ -45dB
• Ultra-Polished Connector ~ -55dB
• Angled Polished Connector up to ~ -65dB
OTDR Series e-Manual, RevE00 Page 37 of 128