| 摘要 |
804,586. Turbidometers. CHIRANA PRAHA NARODNI PODNIK, and VOTOCEK, E. April 24, 1956, No. 12582/56. Class 97(3) Apparatus for determining the number of micro-organisms in the air comprises a Petri dish, a second dish adjacent thereto and co-axial therewith and provided with a radial slot, means for effecting relative rotation of the Petri dish and the slotted dish, and a suction device for drawing air through said slot and over the agar on the Petri dish. In the form shown the Petri dish 8 is carried on a plate 9 rotated by a synchronous motor 10 controlled by a device 11 to make one rotation in 60 seconds. The Petri dish is surmounted by a dish 5 having a radial slot 6 and screw threaded to be adjustable in a mount 4. The dish 5 is transparent and is adjusted until a projection from the underside contacts the agar in the Petri dish. Air is drawn into the apparatus through the the slot 6 by a fan 12 driven by a motor 13.
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