3M Dynatel 7550 Series - Locating Frequencies; Active Frequencies; Power Frequencies

78-9000-5020-0 Rev C 35
9. Locating Frequencies
A. Active Frequencies
Active frequencies are trace signals supplied by a 3M
™
Dynatel
™
Transmitter 7500 Series
(577 Hz, 1 kHz, 8 kHz, 33 kHz, 82 kHz or 133 kHz /200 kHz).
• Select the same frequency that the transmitter is generating.
• Press Menu/OK [6] (you may have to press Menu twice to toggle to the LOCATE
MENU display).
• Press Cable/Pipe [SK]
• Press Freq [SK]
• Press Active [SK Toggle] until the desired frequency is displayed: (“Active” 577, 1k,
8k, 33k, 82k or 133k/200 kHz)
• Press Menu/OK [6] to return to Locate mode.
B. Power Frequencies
7550/7573 Locator
Power frequencies refer to 50 or 60 Hz signals, and their harmonics, that can be traced
without the use of a transmitter.
60: Best for general locating of passive power.
60H (high harmonic): If the 60 choice appears to be responding slowly, or poorly, then
60H is the second choice for locating passive power.
60L (low harmonic): Third choice for passive power locating. May be used when 60 or
50H is weak or erratic.
7550E/7573E Locator
50: Best for general locating of passive power.
50H (high harmonic): If the 50 choice appears to be responding slowly, or poorly, then
50H is the second choice for locating passive power.
50L (low harmonic): Third choice for passive power locating. May be used when 60 or
60H is weak or erratic.
100 Hz: Used for locating rectied AC power signals, often found on pipelines using
impressed current cathodic protection.
120 Hz: Used for locating rectied AC power signals, often found on pipelines using
impressed current cathodic protection.
• Press Menu/OK [6] (you may have to press Menu twice to toggle to the LOCATE
MENU screen).
• Press Cable/Pipe [SK].
• Press Freq [SK].
• Press Power [SK Toggle] until the desired frequency is displayed: (“Power” 60, 60L,
60H, or 120).
• Press Menu/OK [5] to return to Locate mode.
All U.S. receivers default to 60 Hz.