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Prothrombin Meter (Evans Elecroselenium Ltd.)

Mount Sinai Pathology Lab · Health Sciences

A metal instrument with a rectangular footprint. The instrument has a warm grey galvanized finish. An angled surface features two prominent dials each of which has a knob and switch below it and a four digit counter to one side. Above this, at the top of the instrument, is a black manufacturer’s label. Below this are two holes corresponding to the two dials.

At the front of an instrument are two switches and two lights. An electrical cord emerges from the rear of the instrument.

Accession Number: 2022.MTS.2

Alternative Name:

Primary Materials: Iron Alloy.


A blue and silver label at the back of the instrument includes the following information: “Serial No. 71/1291”; “Amps 2A”; “Voltage 110”; “~ 60”
An orange label on the rear of the instrument reads as follows: “ontario hydro// approved// special inspection series T”

Dimensions (cm):

Height = 15.4, Width = 28.5, Length= 38.


A prothrombin meter is used to determine the clotting tendency of blood, for instance, to diagnose a bleeding disorder or to measure the effects of an anticoagulant. The instrument uses a photoelectric system to determine the clotting time of a prepared sample of blood once a reagent has been added. The instrument incorporates a mechanism to keep the sample at a constant temperature.


This instrument is in good cosmetic condition. There are subtle signs of wear and light scratches on the surface fo the instrument. The covering of the electrical cord has been damaged where it meets the body of the instrument.

Associated Instruments:


Evans Elecroselenium Ltd.; Halstead, Essex, England.

Date of Manufacture: c. 1960s – early 1970s.


The Mount Sinai Pathology Lab collection was transferred from a display case on the 6th floor of Mount Sinai Hospital (600 University Ave. Toronto, On) over several days in mid-December 2020.

Additional Information and References:

A. G. Jacobs and J. A. Freer. “Use Of A Prothrombin Meter For Quick’s One-Stage Test.” The British Medical Journal, Vol. 2, No. 5363 (Oct. 19, 1963), pp. 978-980. (Accessed: November 26, 2022).

The Science Museum Group has a similar instrument in their online catalogue. One can see subtle differences in construction between the two examples. (Accessed and archived November 26, 2022).

Historical Notes:

The prothrombin meter automated a diagnostic test (“Quick’s one-stage method”) developed by American hematologist Dr. Armand James Quick (1894 – 1978). The instrument was developed in the late 1950s by physician M. Toohey and senior technician I. J. Y. Cook of the New End Hospital in London.

  • Donated to UTSIC