Abstract: The modification method for the gas density relay, the gas density relay with the online self-check function and the check method thereof provided by this application are used for high-voltage and medium-voltage electrical equipment, including a gas density relay body, a gas density detection sensor, a temperature regulating mechanism, an online check contact signal sampling unit and an intelligent control unit. Regulate temperature rise and fall of the temperature compensation element of the gas density relay body through the temperature regulating mechanism, which leads to a contact action of the gas density relay body, the contact action is transferred to the intelligent control unit through the online check contact signal sampling unit, and the intelligent control unit detects the operating value and/or return value of the contact signal of the gas density relay body based on the density value at the time of contact action.

Abstract: A system and device for monitoring the content of a gas/liquid or gas only containment vessel such as a cylinder is provided. The disclosed apparatus is easily affixed to a standard gas cylinder and configured to monitor the pressure of the cylinder contents and activate a visual and/or audio alarm when the contents of the gas/liquid cylinder are no longer in a liquid or partially liquid state as well as activate another visual and/or audio alarm at a prescribed pressure when the contents of the cylinder are nearing depletion.

Abstract: A bed control device is disclosed. An illustrative embodiment of a pneumatic bed control device includes a housing, multiple pneumatic switches carried by the housing, a plug connected to the pneumatic switches and multiple puff tubes connected to the pneumatic switches, respectively. A joystick-actuated bed control device is also disclosed.

Abstract: A dimension sensor is used in conjunction with a tube and includes a body member and at least one detector element. The body member has an inner surface defining an opening sized to receive the tube. The at least one detector element is connected to the body member and has a detector portion extending into the opening. When the tube is received in the opening, the detector portion is initially disposed apart from the tube. A method using the dimension sensor stops expansion of the tube expanding from a pre-expanded state to a desired expanded state. A pumping device is actuated to pressurize a fluid by an amount sufficient to cause the tube to expand from the pre-expanded state to the desired expanded state. When the tube expands to the desired expanded state, the pumping device deactivates thereby stopping expansion of the tube at the desired expanded state.

Abstract: A variable differential adjustor for a fluid pressure-actuated switch, with the fluid, in the preferred form of the invention, being air. The restrictor has a restrictor housing with a fluid passage in which a restrictor plug, typically a set screw, is engaged. By judicious adjustment of the position of the set screw, fluid flow to and from a pressure-actuated switch is controlled, controlling when the switch is activated to control apparatus such as a sump pump, and when the switch is deactivated.