Abstract: An improved closed-end manometer which overcomes the problems associated with prior U-tube manometer devices. The invention comprises a small bore tube which is transparent or translucent at least along the measuring portion and which may be of tapered or cylindrical bore, a permanent closure at one end of the tube, a relatively small indicating slug formed of a suitable liquid, a measuring scale to note the position of the liquid slug, and a measured quantity of a selected gas between the closure and the nearest end of the liquid slug. The open end of the tube is connected to the vessel or system whose pressure is to be measured or monitored. One feature of the present invention is its ability to provide quantitative pressure indications over a wide range of pressures, or the invention may be calibrated to provide increased sensitivity over a relatively short measuring range. Another feature of the invention is its ability to provide accurate pressure measurements regardless of the instrument's orientation.

Abstract: A novel chemical dispenser for dispensing a predetermined volume of a chemical solution into a body of liquid, such as water in a toilet tank, in response to a change in the level of the liquid comprises a container which holds the solid chemicals to be dispensed, an air vent extending from the top of the container, and a siphon which enters the container through a deck located below the top of the container and has a U-shaped bend extending above the top of the container but below the top of the air vent. The dispenser structure provides substantial isolation of the chemical solution in the dispenser from the surrounding tank water between flushes without the presence of any isolating air bubbles and also provides a color change signal indicating when the solid chemical within the dispenser is depleted.