AC Clamp-on Meter Model CM 660 / CM 670 / CM 685
19
4.6 Frequency Measuring Using Current Input
20 to 4000Hz (2 ranges)
• Turn the rotary switch to the range
• Press the SELECT button to measure the frequency (
will
appear on the display)
• Clamp the jaws around the conductor to be measured
• Press the SELECT button to display the current
Warning:
“-----” indicates that A <2A and F <20Hz