Fluke Networks CertiFiber Pro Users Manual - Manual (Page 141)

Chapter 3: How to Certify Twisted Pair Cabling
About dB Rules
119
67 dB Rule
At frequencies where PS FEXT is less than 67 dB, PS ACR-F cannot
fail. See Tables 3 and 6 for applicable limits.
70 dB Rule
These rules applies to all channel or permanent link test limits
where ACR-F is measured.
At frequencies where FEXT is less than 70 dB for the pair used as
the receive pair for the FEXT test, ACR-F cannot fail.
See Tables 4, 5, and 6 for applicable limits.
Table 3. dB Rules for TIA Permanent Link Test Limits
Measurement Cat 5e Cat 6 Cat 6A
Return Loss 1 3 dB 3 dB 3 dB
NEXT 2 4 dB 4 dB 4 dB
PS NEXT 2 4 dB 4 dB 4 dB
PS ACR-N 2 4 dB 4 dB 4 dB
ACR-F 3 67 dB
1. If insertion loss is less than 3 dB, Return Loss measurements are ignored.
2. If insertion loss is less than 4 dB, these measurements are ignored.
3. If FEXT is less than 67 dB, ACR-F measurements are ignored.