Chapter 14 Reference
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14.1 Measurement Category
Oscilloscope measurement category
tBook minim series oscilloscopes are primarily used for measurements in Measurement Category I.
Measurement category definitions
Measurement category 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.
In the latter case, transient stresses are variable; for that reason, the transient withstand capability of the equipment
is made known to the user.
Measurement category II is for measurements performed on circuits directly connected to the low voltage
installation. Examples are measurements on household appliances, portable tools and similar equipment.
Measurement category III is for 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, for
example, stationary motors with permanent connection to the fixed installation.
Measurement category IV is for measurements performed at the power source of the low-voltage installation.
Examples are electricity meters and measurements on primary overcurrent protection devices and ripple control
units.
Transient withstand capability
Maximum input voltage of the analog input
Category I 300Vrms, 400Vpk.
14.2 Pollution Degree
Pollution Degree
tBook mini series oscilloscopes can operate in environments with
pollution degree 2 (or pollution degree 1).
Pollution
Degree
Categories
Pollution degree 1: No pollution or only dry, non-conductive pollution
occurs. The pollution has no influence. For example: a clean room or air-
conditioned office environment.
Pollution degree 2: Normally only dry, non-conductive pollution occurs.
Occasionally temporary conductivity caused by condensation may occur.
For example: general indoor environment.
Pollution degree 3: Conductive pollution, or dry, non-conductive pollution
occurs which becomes conductive due to condensation. For example: