I. This unit is a multi-range electronic measuring
instrument designed to eliminate the necessity for the
provision of a wide range of separate instruments normally
required for the testing and setting-up of radio, radar and
electronic equipment. It provides 97 ranges of measurement
covering DC and AC current and voltage, resistance, and
power output and has been designed for use under
pan-climatic conditions. The accuracy on DC ranges is ^ 2
per cent FSD and on AC voltage ranges it is ± 3 per cent FSD
measured at 50 c/s.
2. The instrument is AC mains operated and may be used on
any supply system of from 105 to 125 volts, 45 to 66 c/s and
195 to 255 volts, 45 to 66 c/s. Connection to the mains
supply is made bv a mains lead and connector which is
provided with the instrument.
3. The mechanical construction of the unit has been designed
to make servicing as simple as possible. The front panel is
of aluminium alloy and bolted to it is a light, braced
aluminium alloy framework of rectangular form which carries
all the components of the instrument with the exception of
those such as switches and the meter which are carried by
the front panel. The majority of smaller components are
arranged on tag-boards, and the construction is such that
are easilv removable for servicing or inspection. All wiring
is made up into cable-forms.
4. The overall size is 16 in. wide, 10 in. high and l2iin.
deep when the unit is enclosed in its metal case. For
protection in transit, a deep metal lid is fitted over the
front of the unit, held in position by four screws, and in
this lid are stowed the various leads and connectors of the
instrument. These include the mains cable, the RF measuring
head unit extension lead, high-voltage multiplier and
multi-range shunt resistors, spare fuses, pilot lamp, and