Tektronix TDS5000B Series Read This First Manual page 9

Installation (Overvoltage)
Category Descriptions
Overvoltage Category
TDS5000B Read This First
Terminals on this product may have different installation (overvoltage) category
designations. The installation categories are:
Measurement Category IV. For measurements performed at the source of
low-voltage installation.
Measurement Category III. For measurements performed in the building
installation.
Measurement Category II. For measurements performed on circuits directly
connected to the low-voltage installation.
Measurement Category I. For measurements performed on circuits not
directly connected to MAINS.
Overvoltage Category II (as defined in IEC 61010-1)
Compliance Information
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