DO4A Issue 3/2001 4
WARNING!
Any interruption of the protective conductor inside or outside the apparatus, or
disconnection of the protective earth terminal is likely to make the apparatus
dangerous. Intentional interruption is prohibited.
When the apparatus is connected to its mains supply, terminals may be live, and the
opening of covers or removal of parts (except those to which access can be gained by
hand) is likely to expose live parts.
The apparatus shall be disconnected from all voltage sources before it is opened for
any adjustment, replacement maintenance or repair.
Any adjustment, maintenance and repair of the opened apparatus under voltage shall
be avoided as far as possible, and, if inevitable, shall be carried out only by a skilled
person who is aware of the hazard involved
Make sure that only fuses with the required rate current and of the specified type are
used for replacement. The use of makeshift fuses, and the short-circuiting of fuse
holders are prohibited.
Whenever it is likely that the protection has been impaired, the apparatus shall be
made inoperative and be secured against any unintended operation and returned to
our factory or Agent for rectification.
2. Introduction
The DO4A is an accurate bench/portable digital ohmmeter for the measurement of
resistance in the range 10µΩto 4000Ω. It offers you the four terminal resistance
measurement method to eliminate the effect of lead resistance. The measured values
are displayed on a 4 digit LCD display; an overflow of the selected range is also
indicated.
Display range 4000
Simple push button selection of the range required ensures the DO4A may be easily
used by unskilled personnel, error and status warnings are illuminated when
appropriate. The utmost care has been used to ensure that the ohmmeter will
withstand an accidental mains voltage applied to the measuring terminals, but it is not
recommended that voltage should be applied.
