GB1249103A - Improvements in or relating to analytical apparatus - Google Patents

Abstract

1,249,103. Sampling and dispensing apparatus. UNITED KINGDOM ATOMIC ENERGY AUTHORITY. 7 Oct., 1968 [19 July, 1967], No. 33179/67. Heading B1X. In a sampling and dispensing apparatus manipulation of piston 5 causes diluent or reagent liquid to be withdrawn through non- return valve 8 and dispensed through non- return valve 10 until the liquid just fills tubes 1 to the horizontal orifices 28. By raising piston 15 a volume of liquid is withdrawn from tubes 1 and simultaneously a volume of sample solution is drawn by suction into tubes 2, the orifices 27 of which are immersed in the sample solution, from where these sample volumes may be dispensed by lowering piston 15 until tubes 1 are again refilled with diluent liquid. During the lowering of piston 15, piston 5 is also lowered so as to cause liquid to overflow each of tubes 1 and be dispensed through tubes 2, although sample solution is always dispensed prior to this overspill of liquid from tubes 1. From the volumes swept out by the pistons in cylinders 13 and 16 the volume of liquid diluent used to wash out tubes 2 can be calculated and calibration marks 30 on tubes 2 enable the volume of sample dispensed to be known. On completion of the dispensing operation, a valve 26 of inlet 29 is opened to admit air under pressure and flush out any residual liquid remaining in tubes 2 or on the surfaces of tubes 1 or vessel 3. The flow rate of liquid in the system is controlled by capillaries 14.