초록 ▼

Apparatus for preparation of calibration gas mixtures comprises an accurate cylinder divided into first and second chambers for two gases to be mixed in exact proportions by a piston which can be displaced by a precise linear distance by a stepper motor driven micrometer; the piston has a valved pas

Apparatus for preparation of calibration gas mixtures comprises an accurate cylinder divided into first and second chambers for two gases to be mixed in exact proportions by a piston which can be displaced by a precise linear distance by a stepper motor driven micrometer; the piston has a valved passage to allow transfer of a thus precisely determined volume from the second chamber to gas in the first chamber at balanced pressures; stirrers, temperature and pressure sensors are provided, a device for introducing vaporized drops to the gas in the first chamber is provided. The apparatus can provide mixtures in the parts per million and parts per billion ranges and one or more apparatuses can be linked to a personal computer.

대표청구항 ▼

An apparatus for use to prepare gas mixtures of accurately known composition which comprises a cylinder having a first end wall at one end and a second end wall at the other end, a piston movable in the cylinder and sealing with the cylinder walls, said piston and cylinder defining a first chamber o

An apparatus for use to prepare gas mixtures of accurately known composition which comprises a cylinder having a first end wall at one end and a second end wall at the other end, a piston movable in the cylinder and sealing with the cylinder walls, said piston and cylinder defining a first chamber on a first side of the piston and a second chamber on a second side of the piston, means defining a hole in the first side of said piston, a first piston rod fixed to the first end wall and slidable into said hole in the first side of the piston and sealing with the hole defining means, means defining a hole in the second end wall, a second piston rod connected to the second side of the piston and exiting from the second chamber through the hole in the second end wall and sealing with the hole defining means therein, a device for causing linear movement and for measuring that movement, said device being couple to and acting on the second piston rod outside the cylinder, the first and second piston rods having the same diameter, a valved passage penetrating the piston from the first side to the second side, stirring means mounted on the piston rod located in at least one of the chambers, valve means for admission of gas to each chamber and valve means for extracting gas from each chamber.