摘要:
A gas chromatography system comprising a sample introduction device, an oven coupled to the sample introduction device and a detector coupled to the oven is disclosed. In certain examples, the oven may be configured to receive a chromatography column in a space in the oven. In some examples, the oven may be constructed and arranged to provide a substantially constant temperature to the space during an analysis stage of the gas chromatography system.
摘要:
A gas chromatography system comprising a sample introduction device, an oven coupled to the sample introduction device and a detector coupled to the oven is disclosed. In certain examples, the oven may be configured to receive a chromatography column in a space in the oven. In some examples, the oven may be constructed and arranged to provide a substantially constant temperature to the space during an analysis stage of the gas chromatography system.
摘要:
A gas chromatography system comprising a sample introduction device, an oven coupled to the sample introduction device and a detector coupled to the oven is disclosed. In certain examples, the oven may be configured to receive a chromatography column in a space in the oven. In some examples, the oven may be constructed and arranged to provide a substantially constant temperature to the space during an analysis stage of the gas chromatography system.
摘要:
The invention relates to an instrument and method for measuring minute quantities of weight, including a pan for holding a sample to be weighed, a chamber for forming an enclosure about the pan, and a hang-down wire coupled to the pan for suspending the pan within the chamber. The pan has volume less than 0.020 cm3 and the hang-down wire has a volume less than 0.01 cm3. The invention may also include a carrier gas, placed within the chamber, having a generally consistent density over changes in temperature.
摘要:
An apparatus for controlling level of cryogenic liquid in a vessel includes a transfer duct to a pressure supply tank. Pressure pulses are applied to the tank at one rate when the level is below a primary sensor in the vessel, and at a lower rate when the level is above the sensor, so as to compensate for intrinsic declination of the level. At startup a constant pressure is applied to the tank until the level reaches a lower sensor, and a relief valve over the tank is opened when the level overshoots to an upper sensor. Turbulence in the vessel is reduced by a pair of coaxial baffles at the liquid inlet to the vessel, and by a housing with tubular extensions enveloping the sensors.
摘要:
An autosampler for manipulating a specimen container into and out of a furnace of a parent instrument is disclosed. The autosampler has upper, lower and middle gripping fingers which grip and stabilize a crimped wire, which has a large bend therein. The middle gripping finger is positioned between and opposed to the upper and lower gripping finger and has a portion at one end thereof sized and shaped to receive the bend of the crimped wire. The gripping fingers grip and hold the crimped wire while a tray table moves to place the specimen container on a hook at the bottom of the crimped wire. If the specimen container is sealed, a hole may be punctured therein by a puncturing apparatus, which has a housing which is movable between an upper and lower position and biased toward the lower position. A pin is positioned inside the housing. When the specimen tray moves into the upper position, the sealed specimen container moves the housing from the lower position to the upper position thereby exposing the pin and causing it to puncture the sealed specimen container. An electrostatic discharge device which includes a housing having a channel thereabout is also provided. A high voltage source is electrically connected to a pin positioned inside the housing and in fluid communication with the channel for supply voltage to the pin and generating multiple free ions as a result thereof. Pressurized gas directs the free ions toward an electrostatic field to neutralize the ions therein.
摘要:
A cryogenic fluid conveying device has removable connection of a metal tube and a receptor for the tube. The receptor is formed of a housing member with an aperture therein for conveying the fluid. A tubular member of resilient PTFE has a bore size so as to be slidingly receptive of the rigid tube. A ferrule is disposed on the tubular member which is positioned in the housing member. An annular nut is threaded onto an end of the housing to constrict the ferrule and thereby constrict an annular section of the tubular member. This constriction provides a sealingly tight fit for the rigid tube such that the metal tube can be inserted into and removed from the tubular member.