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Calculators in the Laboratory

In the days before personal computers were invented, printing calculators were often used as the basis of "data acquisition systems" to record measurement results in laboratory and industrial applications. Here are some typical examples of laboratory calculators from the 1960s and 70s (click on the pictures to enlarge).

Victor1.jpg (5kb) Victor Model 12-08-121, S/N 2444-899
Technology: Mechanical, electric motor drive
Digits: 8 digit pinbox, 12 digit printer
Dimensions: 8"W x 13-1/2"D x 7"H
Manufactured: Chicago, USA

This "Victor" electro-mechanical printing calculator from the 1960s has a screwed-on metal cover over the keyboard, which severely limits its usefulness as a calculator.

VictorInternal1.jpg (7kb)

Closer investigation reveals that ten electrical solenoids have been fitted over the digit keys, with a larger solenoid over (presumably) a "Print" or "Non-Add" key. The keytops have been removed, so that the solenoid plungers bear directly on the key shafts. The key escutcheon has been surgically removed from the case to make room for the solenoid mounting plate and the protective cover. The calculator did nothing more than provide a printed record of the test results, but that in itself was an achievement in the days before low-cost electronic printers were readily available. The un-used holes in the solenoid plate suggest that there may have been a "de luxe" model with more elaborate features. This calculator was originally supplied by the Technical Measurement Corporation for an instrument in a chemical laboratory.


Triumph1205P.jpg (5kb) Triumph Model 1205P, S/N 61 06 4188
Functions: ASMD, constant, totals, percent, no memories
Technology: MOS-LSI, mains power
Display: 12 digits, printer only
Dimensions: 9-1/2"W x 13"D x 4"H, weight 10 pounds
Manufactured: Triumph AG, Nurnberg, Germany, 1976

This "Triumph" electronic printing calculator from the mid-1970s was modified by the Mettler company of Zurich to serve as a data logger and processor for their range of precision laboratory balances. A custom interface board has been fitted inside the calculator, with a stiff 50-way cable extending from the left-hand side to connect to the balance. Data transfer can be initiated by the extra grey button added to the left-hand side of the front panel, or from a foot switch attached to the balance. The interface has a capacity of 8 BCD digits, and can acquire and print a reading in about 1.5 seconds. The calculator remains fully operational, allowing the operator to calculate and print totals, averages, deviations, net/tare weights, unit conversions, and piece counts.


HP97S.jpg (6kb) HP 97S I/O Calculator, S/N 1830A06816
Functions: Advanced scientific functions, RPN entry
Programming: Fully programmable, magnetic card storage
Technology: MOS LSI, battery power
Display: 9 digits, 2 exponents, LED and printer
Dimensions: 9"W x 8"D x 2-1/2"H, weight 3 pounds
Manufactured: HP USA, 1978

The "97S I/O Calculator" is Hewlett-Packard's HP97 programmable desk calculator (1976) which has been factory-fitted with a general-purpose BCD interface module. The module measures 4"W x 8"D x 1-1/4"H, weighs only half a pound, and is permanently attached to the calculator by a short cable. A standard 50-way "Telco" connector connects the interface to the desired instrument. The interface has 40 input lines for 10 BCD digits, 5 control lines, and 4 output lines corresponding to the software flags within the calculator. With the advanced calculating, programming, and printing functions of the HP97, it was possible to develop quite complex software for data acquisition and analysis. This particular machine was originally supplied with a UV-Visible spectrophotometer from Pye-Unicam, and included a full suite of supporting programs on HP's miniature magnetic cards.

Original text and images Copyright (C) John Wolff 2002.
Use at own risk; beware of errors; suggestions for improvement welcome.
Last Updated: 2 July 2002

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