256 COLLEGE OF ENGINEERING

STANDARDS LABORATORY. Instructional work in courses dealing with
electrical instruments and meters and the official standardizing work for the
Railroad Commission of Wisconsin are carried on in this laboratory. The
laboratory equipment includes a complete duplicate set of standard resist-
ance units and a group of standard cells which are periodically used in con-
nection with the Wolff potentiometer to calibrate the secondary or working
standard instruments. The working standard instruments include numer-
ous Weston, Westinghouse, General Electric and Siemens-Halske precision
and portable ammeters, voltmeters, wattmeters, and a Brooks deflection
potentiometer.

Specialized equipment, such as Wheatstone bridges, a Kelvin double
bridge, and a Per Cent bridge accurate to within 0.01%, are available for
special and precise resistance measurements. For unusual measurements
with instruments, power factor meters, frequency meters, low range am-
meters, voltmeters, wattmeters and low power factor wattmeters are avail-
able. Variable speed motor-generator sets operated in conjunction with a
120 volt storage battery furnish power at any frequency between 10 and
150 cycles. A motor-generator set and a Seth-Thomas clock and relay
timing system are part of the permanently installed equipment for accu-
rately testing portable standard watthour meters.

Equipment suitable for field tests includes stop watches, wattmeters,
ammeters, voltmeters, power factor meters, cycle counter, synchronous
timer, frequency meters, portable standard a. c. and d. c. watthour meters,
phase shifting transformer and voltage regulator, Silsbee current trans-
former testing set, standard current and voltage transformers, and a West-
inghouse three element oscillograph.

PHOTOMETRIC LABORATORIES. These laboratories comprise a number of
rooms especially arranged for the study and testing of lamps and light
sources of various kinds. The equipment includes a complete set of photo-
metric standard lamps, a 300-cm. photometer bar, a 500-cm. photometer bar
equipped with a single mirror selector, a 72” Ulbricht spherical photometer,
a Sharp-Millar portable photometer, a Lummer-Brodhun spectro-photometer
and numerous auxiliary equipment, such as sight boxes of the Bunsen,
Lummer-Brodhun, and flicker types, rotating sectored discs and absorption
screens.

HicH TENSION LABORATORY. The high tension equipment comprises a
50,000-volt, 20-kw. and a 300,000-volt transformer, and an induction regu-
lator permitting the voltage to be gradually varied from zero to 300,000
volts, needle and sphere gaps for measuring high voltages, facilities for
testing insulators under wet weather conditions, and general facilities such
as vibrator type and cathode ray oscillographs, for routine tests or special
researches upon insulating materials.

COMMUNICATIONS AND CIRCUITS LABORATORY. Under telephone equip-
ment may be listed: demonstration panels and sets containing all the ele-
ments from one subscriber’s telephone set through two exchanges to a sec-
ond subscriber’s station, an artificial telephone line having a length of sev-
eral wave lengths, duplex telegraph sets, a repeating station, loading coils
and wave models which show the distribution of current and voltage along
long lines, alternating current bridges and voltmeter-ammeter amplifiers.

The radio equipment comprises a large antenna and the necessary facil-
ities for setting up and carrying on studies relating to sending and receiv-
ing sets such as a stock of receiving and power tubes, inductances, con-