A.W. Sperry Instruments DSA-2002P Operating Instructions Manual - Caution

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CAUTION

●Make sure that the function selector switch is set to an appropriate

position before making measurement.

●Always make sure to insert the plug of each lead fully into the

appropriate terminal on the instrument.

●Be sure to set the function selector switch to the "OFF" position

after use. When the instrument will not be in use for a long period

of time, place it in storage after removing the batteries.  

●Do not expose the instrument to the direct sun, extreme temperatures

or dew fall.

●Use a damp cloth and detergent for cleaning the instrument.  Do

not use abrasives or solvents.

○

Measurement categories (Over-voltage categories)

To ensure safe operation of measuring instruments, IEC61010

establishes safety standards for various electrical environments,

categorized as CAT

Ⅰ to CATⅣ, and called measurement

categories. Higher-numbered categories correspond to electrical

environments with greater momentary energy, so a measuring

instrument designed for CAT

Ⅲ environments can endure greater

momentary energy than one designed for CAT

Ⅱ.

CAT 

Ⅰ : Secondary electrical circuits connected to an AC electrical

outlet through a transformer or similar device.

CAT 

Ⅱ : Primary electrical circuits of equipment connected to an

AC electrical outlet by a power cord.

CAT 

Ⅲ : Primary electrical circuits of the equipment 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).

Incoming wire

CAT.IV 

Interior wiring

Transformer 

CAT.I 

CAT.II

CAT.III 

Socket