Characteristics and Specifications 9 
184 Agilent U1602B/U1604B User’s and Service Guide 
Measurement Category
The U1602B and U1604B oscilloscope is intended to be used for 
measurement in Measurement Category III, 300 V for scope measurement 
and Measurement Category III, 300 V and Category II, 600 V for 
multimeter measurement.
Measurement Category Definitions
Measurement CAT I is for measurements performed on circuits not 
directly connected to MAINS. Examples are measurements on circuits not 
derived from MAINS, and specially protected (internal) mains- derived 
circuits.
Measurement CAT II are measurements performed on circuits directly 
connected to the low voltage installation. Examples are measurements on 
household appliances, portable tools and similar equipment.
Measurement CAT III are measurements performed in the building 
installation. Examples are measurements on distribution boards, 
circuit- breakers, wiring, including cables, bus- bars, junction boxes, 
switches, socket- outlets in the fixed installation, and equipment for 
industrial use and some other equipment including stationary motors with 
permanent connection to the fixed installation.
Measurement CAT IV are measurements performed at the source of the 
low- voltage installation. Examples are electricity meters and measurements 
on primary over current protection devices and ripple control units.