The pictures shown are of an identical calculator from an opened package. It was sealed on December 31, 1963.It comes in a green sealed paper bag with a content sticker and date packed sticker with the packer's initials. The green bag is then sealed in plastic. It was made by B.
(Blundell Rules Limited) and is constructed of three disks of thin plastic with a clear plastic cursor line and metal center. The sliderule has a diameter of approximately 5 inches.
Some of the printing on the front face: METER READING MILLIROENTGENS PER HOUR -- TIME AFTER BURST ACTIVITY TOLERANCES -- DILUTION FACTOR WATER ACTIVITY MICROCURIES PER C. - TIME AFTER BURST Some of the printing on the back side: Inter-Services Ct.
SET TIME AFTER BURST, disc'A,' AGAINST DILUTION FACTOR. SET CURSOR LINE AGAINST METER READING, disc'A. TOLERANCE LEVEL OF ORIGINAL UNDILUTED SAMPLE APPEARS UNDER CURSOR LINE, disc'B.
SET TIME AFTER BURST, disc'C', AGAINST ARROW'T,' disc'B. SET CURSOR LINE TO METER READING, disc'A.TOTAL WATER ACTIVITY OF ORIGINAL UNDILUTED SAMPLE IN MICROCURIES/C. APPEARS UNDER CURSOR LINE, disc'C. Luton, England Please check my other listings for more slide rules and related items. This item is in the category "Collectibles\Science & Medicine (1930-Now)\Engineering\Slide Rules". The seller is "baja_ron" and is located in this country: US. This item can be shipped worldwide.