Inductance bridge, with connecting leads (3) and operating manual, metal / wood / plastic / glass / paper, made by Siemens, Munich, Germany, 1957, used by Defence Standards Laboratory, Adelaide, South Australia, 1957-1977, and CSIRO, Woodville North, South Australia, c. 1977-1990
The bridge has a frequency range of 200 Hz to 50 kHz (Hz=cycles per second). Its measuring range for inductance is 0.1µH TO 1000H (h or H=Henrys) adjustable with three decadic multiplier dials (0-11)x100, x10, x1; one continuous multiplier dial (0-11)x0.1; and on the range switch with 9 positions x10exp-8 to x1h. Resistance covers 1mohm to 100kohm adjustable with two decadic multiplier dials (0-11)x10, x1; one continuous multiplier dial (0-11)x0.1; and with seven partial ranges x10exp-3 to 10exp+3 ohms. A separate switch selects AC or DC measurements, and DC or AC voltage measurements across the specimen inductance. Dials, switches and tops of jacks are black [ebonite].
The measuring error for DC resistance is +/-2%; for AC resistance +/-5% +/-10 milliohms. Capacitance between the terminals Lx 1,2 is approximately 35 µµf (f=farads). Initial inductance is approximately 30 mµh.
The bridge uses a Maxwell circuit. The bridge has separate sockets to connect an alternating or direct current generator, a single frequency oscillator and detector unit, a voltmeter, and galvanometer. There are two pairs of jacks to connect specimen inductors. One pair of jacks connects with the earth of the chassis of the unit.
Lid: The unit is built into black wooden case with removable top kept in place with four clips. The manual and connecting leads can be kept in the box.
Connecting leads: There are three (3) sets of connecting leads. All leads have one end terminating in a three pin plug. The other end of two leads terminate with a set of red, white and black banana-type plugs and one lead terminates with a two pin chromed metal plug. (The manual has a handwritten note which refers to five sets of leads but there are only three with the unit.)
Operating manual: The 13-page manual addresses electrical data, function, operation, size and weight of unit and accessories, with 3 additional pages of circuit and layout of the measuring set-up diagrams. The first page of the manual is printed with the date February 1957.
Small metal plates are affixed to the outside of the box and on face of the unit - black background with white lettering:
0.1µH TO 1000H; 0.2 TO 50 KC/S
Rel 3R 114e (model number)
F-Nr.5/278620 (serial number)
Small sticker on face of unit is printed 'MADE IN GERMANY'.
Sticker on face of unit;
'THIS EQUIPMENT IS THE PROPERTY OF
COMMONWEALTH OF AUSTRALIA'
over which is a paper sticker typed:
The Commonwealth of Australia sticker is engraved however this engraving is indecipherable due to the paper sticker covering it.
On the right end of the wooden box near the handle is a white sticker with black writing which reads
CAL. / / INITIALS'