Sphere's Wonderful World of Perrygrafs and Slide Charts

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Welcome To The Sphere Research Slide Rule Universe archives. Learn about the amazing world of paper and plastic film rules called slide charts!

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The Wonderful World of Perrygrafs and Slide Charts

Not all slide rules are formidable wood and plastic monsters. Some of the most useful and commonly used rules are inexpensive cardboard or thin plastic "purpose built" devices. One of the original, and largest makers of these specialized rules was Perrygraf, originally based in Maywood, Illinois. They were very ingenious at adapting basic slide rule concepts into product selectors, parameter analyzers, and dedicated calculators of all kinds. Perrygraf was sold in 1968 to Nashua Corporation, which moved the company operations to Los Angles, California, and to Puerto Rico. James E. Johnson, formerly of Perrygraf, didn't want to move in the new re-organization, and continued to make and design slide charts in his home. He also eventually took on the private customers of Perrygraf founder Oscar Perry after he passed away, and founded American Slide Chart in 1970. American Slide Chart was very successful, and eventually took over former competitor Perrygraf itself in 1988, making it the largest producer of this type of slide rule product, as well as pop-up 3D calendars. Founder James E. Johnson died in 1988 and the business is now run by his three sons, James D., David and Craig Johnson. Perrygraf and American Slide Chart continue to run and operate as individual companies, and often compete for the same customers.

Some of these rules have been fairly primitive, but many are very sophisticated, and extremely useful for specific problem solving. The electronics industry has been a big user of these devices as product promotions and component specifier guides. The examples here are mainly from my own personal collection over the years, and give a good idea of what is possible with this technology. These devices are still made today, and are one of the very few slide rules still in production. Where applicable, both side of the rule are shown. Clicking on the THUMBNAIL will bring up a larger view.

Notes: Sizes are given as the over-all size of the rule itself. CAUTION, the images while compressed JPEGs, are large in size to show the rule details, and may be slow loading from remote sites.

YOU CAN STILL GET THESE! This type of rule, often called a "Slide Chart", is still manufactured, and here's where to go and get them. Thanks to Craig Kielhofer and his excellent detective work, we can now give you this contact information on current manufacturers. They even have WEB SITES! just click on the company name to go there.

CLICK To Visit Datalizer Slide Charts!

Email Judy Studenski at Datalizer for Information HERE.

American Slide Chart Co.
Largest maker, and now the parent corporation of
Perrygraf, has many stock designs for quick delivery.
25 W. 550 Geneva Road.
Wheaton, IL 60187
Phone: (630) 665-3333 / (800) 323-4433
E-mail: amslide@americanslidechart.com

CLICK to Visit!
Phone: (818) 993-1000 / (800) 665-3333
E-mail: design@perrygraf.com
Visit their new website HERE!

Alcott Calculator Company
PO Box 547396
Orlando, Florida 32854
Phone: (407) 295-5457 Fax: (407) 295-4464

CLICK HERE to Visit IWA in 3 Languages, with virtual working rules!
IWA Incorporated
attention: Christopher E. Gabbert
819 Newberry Drive, Batavia
Il 60510 USA

Tel: +1 630 879 1900
Fax: +1 630 879 1966
E-mail: cg@iwa-slidecharts.com

Manufacturer Customer	Slide Rule Type	Size, Core Material	Scales Features	IMAGE LINKS (Back to Return)
SEARS	Duplex 3764	8" Gray and Clear Plastic	Universal Metric Converter, length, area, volume, weight, temperature. Plus a basic C/D slide rule.
Perrygraf Greey Lightnin	Duplex	8" White Cardboard	Volumetric calculator for all shapes.
Perrygraf Instrument Specialties	Duplex	8" White Cardboard	Shielding calculations. Abosorbtion loss, plane wave loss. Electric/magnetic field reflection loss.
Perrygraf Tadiran	Duplex	8" White Cardboard	Battery performance calculator, battery selector.
Philips	Duplex	8" Plastic	Multiple metric converters, formulas. C/D Scale slide rule.
Vibrachoc	Duplex	8" White Cardboard	Deflection, g-forces, velocity, frequency. Extensive mechanical force calculations for vibration related issues. Cover contains operating manual.
Perrygraf Spectrum Control	Duplex	8" White Cardboard	Voltage/dB/Watts conversions. Wave formats.
Perrygraf Bird	Simplex	8" White Cardboard	VSWR, loss, reflected power calculations. Rulers on one side
Perrygraf Sensym	Simplex	8" White Cardboard	Temperature, pressure calculations. Conversion factors on one side.
Anitec	Simplex Circular	5" White Plastic	Image sizing calculator (photreduction/enlargement)
Perrygraf General Semiconductor	Duplex	8" White Cardboard	Transient/impulse voltage calculations, device selector.
Kemet	Duplex Microfarad Manipulator	8" Clear/Tan Plastic	Capacitive reactance, ESR, ripple voltage, power calculations.
Guco Raychem	Simplex Circular 1004	5" White Plastic	Calendar Date finder.