摘要:
A method and apparatus for sensing different levels of liquids in their respective containers in a liquid-consuming and/or producing instrument system. According to a preferred embodiment, an elongated liquid-sensing probe having axially spaced electrodes adapted to sense liquid at multiple levels is arranged in each container of liquid. A controller, e.g. a suitably programmed microprocessor, operates to selectively poll different pairs of electrodes carried by the probe to determine whether or not the polled electrode pairs are immersed in the contained liquid. Preferably, the polling circuit comprises an electronically-controlled resistor that serves to normalize the level-sensing output signal for liquids of different bulk resistivity.
摘要:
A liquid aspiration device comprises an aspiration tube that slideably engages an opening in a cap such that a head on the end of the aspiration tube is moveable with respect to the opening in the cap. A tube cover is positioned between the opening in the cap and the head of the tube. The tube cover is operable to collapse into the cap when the head is moved into the cap. When the head and the tube cover are moved into the cap they are shielded from potential contamination that may occur when the aspiration device is moved from one container to the next. A lock is positioned in the cap. The lock is operable to move between an engaged position where the head may be retained within the cap and a disengaged position where the head is free to pass into or out of the cap.
摘要:
A pressure equalization method and system is provided for starting a compressor while maintaining the condenser at a high pressure and includes a valve and a bleed port. The compressor has a compressor inlet for receiving a fluid at a first pressure and a compressor outlet for discharging the fluid at a second pressure, and is operable to compress the fluid from the first pressure to the second pressure. The valve is proximate to and in fluid communication with the compressor outlet and is movable to an open position when the compressor is operating to permit the fluid at the second pressure to flow through the valve and is movable to a closed position when the compressor stops operating to prevent backflow of the fluid at the second pressure through the valve toward the compressor inlet. The bleed port is upstream of the valve and in fluid communication with the compressor inlet to equalize the pressure of the fluid contained in the compressor when the compressor stops operating.
摘要:
Method and apparatus for controlling the temperature of one or more reaction vessels in a bio-chemical analyzer comprises a heat-exchange block, preferably made of cast aluminum or the like, and a thermoelectric device for heating or cooling the block to within a desired temperature range. The heat-transfer block cradles one or more reaction vessels in a thermal energy-transferring relationship, and further supports, in a thermal energy-transferring relationship, one or more fluid conduits serving to transmit a liquid or gas to the interior of the reaction vessels. Preferably, the heat-transfer block is cast from aluminum, and the fluid conduits are disposed inside the casting. By supporting the reaction vessel(s) and fluid conduit(s) in a common block, a single thermoelectric device and controller can be used to simultaneously control the respective temperatures of multiple fluid reagents and/or gases, as well as one or more reaction vessels, thereby reducing the power requirements of the thermal control system.
摘要:
A method for preventing either the introduction of air into a liquid aspirated from a container through an aspiration line passing through a container cap, or the over-filling or non-filling of a container by a liquid dispensed through a dispensing line passing through a container cap. Such method comprises the steps of simultaneously detecting that (a) the container cap is properly positioned on and secured to a liquid container from which liquid is to be aspirated, or into which a liquid is to be dispensed, and (b) detecting that the level of liquid in the container is either above or below a predetermined level
摘要:
A method and apparatus for sensing different levels of liquids in their respective containers in a liquid-consuming and/or producing instrument system. According to a preferred embodiment, an elongated liquid-sensing probe having axially spaced electrodes adapted to sense liquid at multiple levels is arranged in each container of liquid. A controller, e.g. a suitably programmed microprocessor, operates to selectively poll different pairs of electrodes carried by the probe to determine whether or not the polled electrode pairs are immersed in the contained liquid. Preferably, the polling circuit comprises an electronically-controlled resistor that serves to normalize the level-sensing output signal for liquids of different bulk resistivity.
摘要:
A liquid aspiration device comprises an aspiration tube that slideably engages an opening in a cap such that a head on the end of the aspiration tube is moveable with respect to the opening in the cap. A tube cover is positioned between the opening in the cap and the head of the tube. The tube cover is operable to collapse into the cap when the head is moved into the cap. When the head and the tube cover are moved into the cap they are shielded from potential contamination that may occur when the aspiration device is moved from one container to the next. A lock is positioned in the cap. The lock is operable to move between an engaged position where the head may be retained within the cap and a disengaged position where the head is free to pass into or out of the cap.
摘要:
A compressor for providing automatic capacity modulation is disclosed. The compressor comprises a compression chamber, a compressing member, a reexpansion area, a flow passage, a valve member, and a biasing member. The flow passage is in fluid communication with the compression chamber and the reexpansion area. In one position, the valve member permits flow through the flow passage and in a second position it prevents flow. The valve member is subjected to a first operating condition of fluid on one side and a second operating condition of the fluid on the other side. The biasing member exerts a biasing force on the valve member. When the first operating condition reaches a predetermined point relative to the second operating condition, the valve member moves and effects a change in the capacity of the compressor.
摘要:
A method for preventing either the introduction of air into a liquid aspirated from a container through an aspiration line passing through a container cap, or the over-filling or non-filling of a container by a liquid dispensed through a dispensing line passing through a container cap. Such method comprises the steps of simultaneously detecting that (a) the container cap is properly positioned on and secured to a liquid container from which liquid is to be aspirated, or into which a liquid is to be dispensed, and (b) detecting that the level of liquid in the container is either above or below a predetermined level.
摘要:
Method and apparatus for controlling the temperature of one or more reaction vessels in a bio-chemical analyzer comprises a heat-exchange block, preferably made of cast aluminum or the like, and a thermoelectric device for heating or cooling the block to within a desired temperature range. The heat-transfer block cradles one or more reaction vessels in a thermal energy-transferring relationship, and further supports, in a thermal energy-transferring relationship, one or more fluid conduits serving to transmit a liquid or gas to the interior of the reaction vessels. Preferably, the heat-transfer block is cast from aluminum, and the fluid conduits are disposed inside the casting. By supporting the reaction vessel(s) and fluid conduit(s) in a common block, a single thermoelectric device and controller can be used to simultaneously control the respective temperatures of multiple fluid reagents and/or gases, as well as one or more reaction vessels, thereby reducing the power requirements of the thermal control system.