User Manual
ii 
Category I (CAT I): Measurement instruments whose measurement 
inputs are not intended to be connected to the mains supply. The 
voltages in the environment are typically derived from a limited-energy 
transformer or a battery. 
Category II (CAT II): Measurement instruments whose measurement 
inputs are meant to be connected to the mains supply at a standard wall 
outlet or similar sources. Example measurement environments are 
portable tools and household appliances. 
Category III (CAT III): Measurement instruments whose measurement 
inputs are meant to be connected to the mains installation of a building. 
Examples are measurements inside a building's circuit breaker panel or 
the wiring of permanently-installed motors. 
Category IV (CAT IV): Measurement instruments whose measurement 
inputs are meant to be connected to the primary power entering a 
building or other outdoor wiring. 
Do not use this instrument in an electrical environment with a higher 
category rating than what is specified in this manual for this instrument. 
You must ensure that each accessory you use with this instrument has a 
category rating equal to or higher than the instrument's category rating 
to maintain the instrument's category rating. Failure to do so will lower 
the category rating of the measuring system. 
Electrical Power 
This instrument is intended to be powered from a CATEGORY II mains 
power environment. The mains power should be 120 V RMS or 240 V 
RMS. Use only the power cord supplied with the instrument and 










