Safety Notes
4
Accuracy
We define measurement tolerances in terms of f.s. (full scale), rdg. (reading) and dgt. (digit) values, with
the following meanings:
This instrument complies with CAT II (1000 V)/ III (600 V) safety requirements.
To ensure safe operation of measurement instruments, IEC 61010 establishes safety standards for vari-
ous electrical environments, categorized as CAT I to CAT IV, and called measurement categories. These
are defined as follows.
Higher-numbered categories correspond to electrical environments
with greater momentary energy. So a measurement device
designed for CAT III environments can endure greater momentary
energy than a device designed for CAT II.
Using a measurement instrument in an environment designated with a
higher-numbered category than that for which the instrument is rated
could result in a severe accident, and must be carefully avoided.
Never use a CAT I measuring instrument in CAT II, III, or IV envi-
ronments.
The measurement categories comply with the Overvoltage Catego-
ries of the IEC60664 Standards.
Other Symbols
Symbols in this manual
Indicates the prohibited action.
(p. )
Indicates the location of reference information.
Indicates quick references for operation and remedies for troubleshooting.
*
Indicates that descriptive information is provided below.
[ ]
Menus, commands, dialogs, buttons in a dialog, and other names on the screen and the keys
are indicated in brackets.
CURSOR
(Bold character)
Bold characters within the text indicate operating key labels.
Windows
Unless otherwise specified, “Windows” represents Windows 95, 98, Me, Widows NT4.0, Win-
dows 2000, Windows XP, or Windows Vista.
Dialog
Dialog box represents a Windows dialog box.
Mouse action terminology
Click: Press and quickly release the left button of the mouse.
Right-click: Press and quickly release the right button of the mouse.
Double click: Quickly click the left button of the mouse twice.
Drag:
While holding down the left button of the mouse, move the mouse and then release the left
button to deposit the chosen item in the desired position.
Activate: Click on a window on the screen to activate that window.
f.s. (maximum display value or
scale length):
The maximum displayable value or scale length. This is usually the name of
the currently selected range.
rdg. (reading or displayed value): The value currently being measured and indicated on the measuring instrument.
dgt. (resolution): The smallest displayable unit on a digital measuring instrument, i.e., the input
value that causes the digital display to show a "1" as the least-significant digit.
Measurement categories (Overvoltage categories)
CAT Ⅰ :
Secondary electrical circuits connected to an AC electrical outlet through a transformer or similar device.
CAT Ⅱ :
Primary electrical circuits in equipment connected to an AC electrical outlet by a power cord (portable
tools, household appliances, etc.) CAT II covers directly measuring electrical outlet receptacles.
CAT Ⅲ :
Primary electrical circuits of heavy equipment (fixed installations) connected directly to the distribution
panel, and feeders from the distribution panel to outlets.
CAT Ⅳ :
The circuit from the service drop to the service entrance, and to the power meter and primary over-
current protection device (distribution panel).
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