Diluters and Dispensers

aluminum frame with a clear polycarbonate front piece that holds the glass valves and have a

handle manually moved through a set arc that draws up or expels solution determined by the

configuration of the glass valves, tubing, probes, and plastic syringes. To adjust the syringe

volumes, allow the handle to remain in the up, stop position. Loosen the wing nut on the syringe

barrel bracket and the round thumbscrew on the bottom of the syringe plunger anchor. Move the

syringe anchor up the rod toward the front for larger volume and down or toward the back for less

volume. Push the syringe barrel down so that the plunger head is at the top of the syringe. Tighten

the thumbscrew and wing nut and check the volume by pushing the handle to the down position.

Failure to adjust volumes in this manner will cause pressure to be applied to the syringe

barrel bracket. The volumes indicated on the syringe are nominal rather than exact. For dilutions, a

nominal value is usually sufficient since standards should be prepared so that they will be diluted in

the same manner as the unknown. The standard curve will then account for the dilution factors. If

exact.dilutions are desired, then a standard solution should be diluted by hand pipet and the value

checked by spectrophotometer or AA, then the volumes on the diluter can be adjusted to match the

hand pipet dilution. Schematic diagram of diluter and dispenser connections.