UB^: >RY 
 STATE PLANT BOARD 
 
 October 19A4 ET-219 
 
 ITNITED STATES DEPARTMENT OF AGRICULTURE 
 
 Agricultural Research Administration 
 
 Bureau of Entomology and Plant (^rantlne 
 
 IKJECTOR FOR FUMIGANTS IN LiqtJID FORM 
 
 By R, D. Chisholm, Division of Insecticide Investigations, 
 
 and W. C. Fest and A, C. Mason, 
 
 Division of Fruit Insect Investigations 
 
 Many devices have been described for the applicaticn, for partictilar 
 purposes, of measured doses of ftaiigants lAich are liquids under ordinary 
 conditions of temperature and pressure. This paper describes an injector 
 which has been found to be useful for the injection into corrugated paper 
 cartons of doses of ethylene dlchlorlde ranging in volume from 1 ml. to 
 21 ml. in steps of 0.5 nl* The cartons contained plant material Infested 
 with Japanese beetle larvae. 
 
 Description of Apparatus 
 
 The injector can best be described by referring to the lettered parts 
 in the drawing (figure l). The barrel (A) is a piece of extra heavy brass 
 pipe reamed to a convenient uniform diameter and of the desired length. The 
 piston (B ) is made from a piece of round brass rod machined to a diameter emd 
 to a length which are both slightly less than the diameter of barrel (A)^. A 
 groove (C2 Is provided in piston (B) to accomodate a closely fitted packing 
 ring lubricated with graphite. Piston (B) is moved by means of screw (D) , the 
 lower end of which is recessed to rotate In split-bushing (E)^ which is screwed 
 Into a hole drilled in the upper end of piston (B) , Split-bushing (E) la made 
 from hexagon- shaped brass rod. The rod is halved vertically. The halves are 
 placed together and drilled to accomodate the recessed end of screw (D), With 
 the exception of l/g Inch, the outside of the halves are then machined and 
 threaded to screw into the hole in piston (B), All parts are fitted closely 
 to reduce lost motion when screw (D) is rotated. Screw (D) extends through 
 a threaded hole in flanged plug (fT, which is screwed tightly into the end 
 of barrel (A), A small-bore tube (G) is fitted in flanged plug (H) , which 
 is screwed tightly against a paper gasket resting on the lower end of barrel 
 (a). Screw (D) is rotated by means of crank (I). The top of flanged plug 
 (F) ig graduated in convenient units. Barrel Ta) is provided with a vent (J) . 
 
 The injector is filled by placing the tip of tubs (G) below the surface 
 of the liquid fumigant and rotating screw (D) in a counterclockwise direction. 
 The fumigant is discharged by rotating screw (D) in a clockwise direction. 
 The injector is calibrated by dividing the voliime per unit length of barrel 
 by the ntunber of threads per unit length of screw, or by measurement of the 
 volume of fumigant actually discharged during each rotation of the screw. 
 
- 2 - 
 
 Usee for Apparatus 
 
 The Injector has "been foiind to be suitable for the ap-nlicaticn of 
 ethylene dichlorlde for Japanese beetle quarantine purToosee, The barrel 
 of the injector used was 5 inches long and had an inside diameter of I-I/16 
 inches and a screw with lU threads per inch. The delivery of ethylene di- 
 chloride per rotation of the screw was calculated to be l.oU ml. Twenty 
 rotations of the screw delivered 21 ml, or aji excess of 0,01 ml, per rota- 
 tion. Tractions of a milliliter are delivered by partial rotation of the 
 screw regulated in reference to the pointed end of the crank and the gradu- 
 ations on the top of the upper flanged plug. 
 
 By selecting the proper barrel diameter and screw pitch the injector 
 may be constructed to deliver other measured doses for a variety of |)urpose8 
 such as soil injections. 
 
FIGURE I. DIAGRAM OF INJECTOR