strength down to 15 per cent of the load, thus reducing current consump. tion and increasing lamp life.
Measuring 3 x 34 x 11⁄2 in. deep, the unit may be easily fitted in any standard 7/8 in. deep MK base with- out modification or spacers, in place of a switch. Installation entails removal of the front plate from the standard on/off switch, connection of the ex- isting wires to the Dimlite terminals and refixing.
Photain Controls Ltd., Randalls Road, Leatherhead, Surrey, UK, are the makers.
FOUNTAIN HEAD
A fountain head developed by CDM Inc., Japan, creates more than ten changing spray patterns automatically. No electrical installation is needed to change the patterns as the inner mech- anism of the head is driven by the hydraulic force of the water supply or of a small submersible pump.
The height of the spray is adjust-
able with the water flow into the
CDM fountain head
head, the best patterns being produced when the flow is 10-15 litres a minute at a pressure of 0.5 1 kg/sq. cm.
Suitable for installation in indoor or outdoor displays the head measures 61⁄2 in. high and 13% in. in diameter.
DOMESTIC BOILER
All domestic hot water requite- ments and full central heating can be provided by the Parca 200M boiler produced by the ASJ Organisation, Linkoping, Sweden.
Its range is rated at 60,000-90,000 BTHU per hour and it is supplied com- plete with pre-wired oil burner, mixing valve and integral copper indirect cy- linder, giving 50 gallons of hot water per hour.
Overall dimensions are 54 in. high x 23 in. wide x 38 in. deep. All tap- pings, as well as the flue outlet, are located on the top of the unit. Tap- pings are provided for the fitting of an immersion heater for use in the event of burner failure.
The 200M has a clip-on detachable casing in two-tone plastic-coated steel.
PAPUA
Parca 200M boiler
It is covered by a ten-year guarantee A second version of the unit has two against corrosion of flue-way surfaces.
separate combustion chambers
―
one
for oil firing and the other for burning
solid fuel or refuse.
DRAWING MATERIAL
Visually of high transparency, but opaque to actinic light in all reproduc- tion processes, Regumask masking film, made by Claus Koenig KG, Paul Gossen Strasse, Erlangen, West Ger- many, can be used to advantage in studios and drawing offices.
in. wide by 98 in. long (629 mm by 2.489m) rolls. The p.v.c.-backed MF 1 offers a further choice of 24% in. by 329 in. (629 mm by 8.356 m) and 40%1⁄2 in. by 137 in. (1.029 m by 3.480 m) sizes.
MOISTURE METER
A self-contained transistorised in- strument designed to detect the water content in various building materials has been introduced by M.O.S. Ltd., Regency House, 63 Preston New Road, Blackburn, Lancs., UK.
The instrument, the Portatrace moi- sture meter, is constructed from cast aluminium and has three scales to determine the moisture content of concrete, timber or plaster and an arbitrary scale which enables the operator to set his own stan- dards. The scales in- dicate whether tim-
sufficiently dry to be ber, for instance, is
painted or whether
dry rot is liable to
set in.
The meter is hand-held and is operated by a 9-volt transistor
Portatrace
Pistol-shaped, it is operated by press-
battery.
ing two metal probes into the surface of the material and by squeezing the trigger.
by Slom Surveying Instruments, Ltd., an optical reducing alidade produced
SURVEYOR'S ALIDADE The film consists of a clear sheet based on either p.v.c. (MF1) or poly-tained without calculations by use of Distances and heights can be ob-
ester (MF2) and covered with a thin red film. In use, the sheet is placed over a drawing, with the red film up- wards, and the areas to be masked are cut round lightly with a sharp blade. This process cuts through the red film but not the clear backing and enables
the superfluous areas of film to be peeled off leaving the masking shapes in the required position relative to each other on the clear sheet.
Since the red film has a slightly self-adhesive quality, it can be stuck to a paper or drawing if laid flat and pressed down.
Paris.
The instrument uses a purely opti- cal principle without any mechanical device. Since surveys can be directly reproduced on the plane-table without calculations and sketches, time is saved in the completion of photogrammetric surveys and preliminary drafts on a scale of 1/200.
The main parts of the alidade are an anallatic telescope, an optoreducing device similar to that of a tacheometer, a revolving post and base-plate. The telescope, which gives an upright image, is movable around a horizontal axis and can be corrected by an adjustable screw.
The post, which revolves about an axis perpendicular to the telescope is accurate horizontally. The post is fixed to a base-plate which also carries a spherical level, a parallel ruler and a control knob for very fine directional
Both types of sheet come in 24% adjustment.
Far East BUILDER, January 1969.
45