Lush cable tester
Inventory Number2012-1-0037
ClassificationTest Equipment
Subject
Maker
Rawson Electrical Instrument Company
1918 - 1968
Cultural Region
Place of Origin
Place of Use
Dimensions15 × 30.5 × 20.2 cm (5 7/8 × 12 × 7 15/16 in.)
Material
DescriptionRectangular walnut case with rounded leather handle, hinged lid and crank on side.
Inside is the instrument, with a bakelite casing.
On top panel fan-shaped window in center of face, with the Rawson standard pointer (with a double, o-shaped section over the mirror) with a reflective band under the scale.
Single scale, from -10 to 120.
Over the scale is a black capped binding post labeled "10000 OHMS", below scale on right is knob labeled "MULTIPLY DIVISIONS BY", "1, 5, 10, 50, 100, 500" and "100 DIVS PER VOLT ON 100000 OHMS"
Under the scale on left are two black capped binding posts top one labeled "+ COMMON" and bottom one labeled "100000 OHMS". Raised disk-shaped section with the "ZERO" and "CLAMP" dials, labeled "UNCLAMP BEFORE USING". At bottom right is knob labeled "PULL FOR CAPACITY ONLY"
Bottom panel two black capped binding posts labeled "METER" top left one labeled "+" and right labeled "-". knob at top right labeled with arrow. Rectangular plug labeled on top "D" and on bottom "C". Two black capped binding posts labeled "BATTERY" bottom left.
At center knob labeled "A LINE CURRENT" "B LINE POTENTIAL" "C END TO FAULT" "D FAULT TO END D" and "K OPEN OR CAPACITY TEST". Two black capped binding posts at bottom.
Inside is the instrument, with a bakelite casing.
On top panel fan-shaped window in center of face, with the Rawson standard pointer (with a double, o-shaped section over the mirror) with a reflective band under the scale.
Single scale, from -10 to 120.
Over the scale is a black capped binding post labeled "10000 OHMS", below scale on right is knob labeled "MULTIPLY DIVISIONS BY", "1, 5, 10, 50, 100, 500" and "100 DIVS PER VOLT ON 100000 OHMS"
Under the scale on left are two black capped binding posts top one labeled "+ COMMON" and bottom one labeled "100000 OHMS". Raised disk-shaped section with the "ZERO" and "CLAMP" dials, labeled "UNCLAMP BEFORE USING". At bottom right is knob labeled "PULL FOR CAPACITY ONLY"
Bottom panel two black capped binding posts labeled "METER" top left one labeled "+" and right labeled "-". knob at top right labeled with arrow. Rectangular plug labeled on top "D" and on bottom "C". Two black capped binding posts labeled "BATTERY" bottom left.
At center knob labeled "A LINE CURRENT" "B LINE POTENTIAL" "C END TO FAULT" "D FAULT TO END D" and "K OPEN OR CAPACITY TEST". Two black capped binding posts at bottom.
Signedprinted on face of meter: DIVISIONS / RAWSON ELECTRICAL INSTRUMENT CO. / CAMBRIDGE, MASS. / NO 4580 / TYPE 501 / PATENTED / MAY 15, 1923 / APRIL 15, 1924 / MAR. 3, 1925 / OTHERS PENDING
Inscribedon paper nailed to inside of lid: spare carbon brushes / for current commutator
bottom of meter scale has a handwritten table of switch settings, voltages, current values etc.
FunctionThis meter was developed chiefly to provide a means for locating high resistance faults in cables without the questionable and dangerous practice of burning the fault down. In development it was found that many other useful features such as Line Resistance, Insulation Resistance and Location of breaks could be included with very little additional work.
