Gradient system
    3.
    发明授权
    Gradient system 失效
    渐变系统

    公开(公告)号:US5234587A

    公开(公告)日:1993-08-10

    申请号:US905742

    申请日:1992-06-29

    IPC分类号: G01N30/34

    CPC分类号: G01N30/34 G01N2030/347

    摘要: To supply a programmed gradient to a high pressure pump for introduction into a column, a mixer, degasser and accumulator communicates with the high pressure pump to supply fluid thereto, having a volumn no more than 150 times the chamber volume of the high pressure pump. The mixer, degasser and accumulator includes temperature sensors which sense when the mixer, degasser and accumulator has been emptied to a level where it cannot respond to a demand for fluid from said high pressure pump and provides a signal to a low pressure pump which responds by cycling to again fill the mixer, degasser and accumulator. Upon receiving a demand signal, the low pressure pump fills by drawing fluid from a plurality of fluid sources to compose the gradient being used at that time, with the pump slowing during valve opening and closing so as to avoid cavitation.

    摘要翻译: 为了向高压泵提供编程梯度以引入塔中,混合器,脱气器和蓄能器与高压泵连通以向其供应流体,其体积不高于高压泵的室容积的150倍。 混合器,脱气机和蓄能器包括温度传感器,其感测混合器,脱气器和蓄能器何时被排空到不能响应来自所述高压泵的流体需求的水平,并且向低压泵提供信号,该低压泵由 循环再次填充混合器,脱气机和蓄压器。 在接收到需求信号时,通过从多个流体源抽取流体来填充低压泵以构成当时使用的梯度,同时在阀打开和关闭期间泵减慢,以避免空化。

    Method for predicting steady-state conditions
    6.
    发明授权
    Method for predicting steady-state conditions 失效
    预测稳态条件的方法

    公开(公告)号:US5040126A

    公开(公告)日:1991-08-13

    申请号:US787016

    申请日:1985-10-15

    IPC分类号: G01N30/32

    CPC分类号: G01N30/32 G01N2030/326

    摘要: To stabilize flow rate in a single-stroke, syringe-type high pressure pump to a constant value after turn-on, a control system; (1) in one embodiment, senses the maximum rate of change of pressure, detects a pressure when the rate of change is two-thirds of the maximum, increases the pump rate until the pressure is three times that at the value of the detected pressure and begins pumping at the preset constant flow rate; and (2) in another embodiment operates a pump system at a flow rate ten times the preset flow rate and, when the time derivative of the pressure has dropped to nine tenths of its maximum, the pump motor speed is reduced to the preset flow rate.

    摘要翻译: 为了将单次冲程注射器型高压泵的流量稳定在开启后的恒定值,控制系统; (1)在一个实施例中,感测最大压力变化率,当变化率是最大值的三分之二时检测压力,增加泵速,直到压力为检测压力值的三倍 并以预设的恒定流量开始泵送; 和(2)在另一个实施例中,以预设流量的十倍的流速操作泵系统,并且当压力的时间导数已经下降到其最大值的十分之一时,泵电机速度降低到预设的流量 。

    Power supply
    7.
    发明授权
    Power supply 失效
    电源

    公开(公告)号:US4933825A

    公开(公告)日:1990-06-12

    申请号:US388767

    申请日:1989-08-02

    IPC分类号: G05F1/613 H02M3/335 H04B10/00

    摘要: To reduce the cost of insulation in a high-voltage power supply capable of constant current or constant power operation, the power supply includes an optical self-powered feedback circuit from its high-voltage section to the low-voltage section to control the output of the power supply. The feedback circuit includes within the high-voltage section of the power supply: (1) a sensing circuit for obtaining an amplitude modulated signal related to current flowing through at least certain output terminals; (2) a voltage-to-frequency converter for converting the amplitude modulated signal to a frequency modulated signal; (3) a pulse shaper for generating pulses having a duration of less than 3 microseconds to reduce power consumption; and (4) a light emitting diode. Light from the diode is transmitted to a low-voltage section where it is utilized in the feedback network. The high-voltage feedback circuitry utilizes less than 75 microamps.

    摘要翻译: 为了降低能够进行恒定电流或恒定功率运行的高压电源的绝缘成本,电源包括从其高压部分到低压部分的光学自供电反馈电路,以控制 电源。 反馈电路包括在电源的高压部分内:(1)感测电路,用于获得与流经至少某些输出端的电流相关的幅度调制信号; (2)电压 - 频率转换器,用于将幅度调制信号转换成调频信号; (3)脉冲整形器,用于产生具有小于3微秒持续时间的脉冲以降低功耗; 和(4)发光二极管。 来自二极管的光被传输到低压部分,在反馈网络中被利用。 高压反馈电路使用小于75微安。

    Method for predicting steady-state conditions
    8.
    发明授权
    Method for predicting steady-state conditions 失效
    预测稳态条件的方法

    公开(公告)号:US4882781A

    公开(公告)日:1989-11-21

    申请号:US415276

    申请日:1982-09-07

    IPC分类号: G01N30/32

    CPC分类号: G01N30/32 G01N2030/326

    摘要: To stablize flow rate in a single-stroke, syringe-type high pressure pump to a constant value after turn-on, a control system: (1) in one embodiment, the control system senses the maximum rate of change of pressure, detects a pressure when the rate of change is two-thirds of the maximum, increases the pump rate until the pressure is three times that at the value of the detected pressure and begins pumping at the preset constant flow rate and (2) in another embodiment, operates a pump system at a flow rate ten times the preset flow rate and, when the time derivative of the pressure has dropped to nine tenths of its maximum, the pump motor speed is reduced to the preset flow rate.

    摘要翻译: 为了将单冲程注射器型高压泵的流量稳定在开启后的恒定值,控制系统:(1)在一个实施例中,控制系统感测最大压力变化率,检测 当变化率是最大值的三分之二时,压力增加,直到压力达到检测压力值的三倍,并以预设的恒定流量开始泵送;(2)在另一个实施例中,操作 泵系统的流量为预设流量的十倍,当压力的时间导数下降到其最大值的十分之一时,泵电机的速度降低到预设的流量。

    Absorbance monitor
    9.
    发明授权
    Absorbance monitor 失效
    吸光度计

    公开(公告)号:US4726680A

    公开(公告)日:1988-02-23

    申请号:US792321

    申请日:1985-10-28

    IPC分类号: G01N21/25 G01J3/42 G01N21/05

    CPC分类号: G01N21/255

    摘要: To reduce noise in an absorbance monitor in which the light source is a deuterium lamp, an aspheric condensing mirror focuses light from an approximately 0.6 mm-high by 2 mm-wide part of the central bright spot in the deuterium lamp through a slit in an aperture plate which blocks all other light and an aspheric monochromator mirror focuses the light onto a plane reflective diffraction grating, which: (1) is mounted for orbiting about an axis parallel to the longitudinal axis of the slit; and (2) adjusted so that, as it orbits it reflects a selected wavelength of light to a beam splitter. Each beam is focused upon and transmitted through a different one of two equal oval apertures optically at least as large as the height of the image of the aperture near the lamp. The beams are converted to an electrical signal by silicon diode photosensors, thus using only light: (1) focused in both transverse planes and originating from the same spot on the central bright spot; and (2) with the same relative geometric weighting for light propagating in various directions from various subparts of the central bright spot. To reduce noise originating from flow-related refraction effects in the flow cell, the flow cell has reflective walls and a large collecting mirror focuses light entry in a large cone from the flow cell into a measuring photocell. This large cone has a wider angle than the cone of light entering the flow cell.

    摘要翻译: 为了降低光源是氘灯的吸光度监测器中的噪声,非球面聚光镜通过氘灯中的狭缝将来自氘灯中的中心亮点的大约0.6mm高×2mm宽的部分的光聚焦 阻挡所有其他光的孔板和非球面单色仪镜将光聚焦到平面反射衍射光栅上,所述平面反射衍射光栅:(1)安装成围绕平行于狭缝的纵向轴线的轴线旋转; 和(2)进行调整,使得当其轨道运动时,它将选择的波长的光反射到分束器。 每个光束被聚焦并透射通过光学上至少与灯附近的孔的图像的高度相同的两个相等的椭圆形孔中的不同的一个。 光束通过硅二极管光电传感器转换为电信号,因此仅使用光:(1)聚焦在两个横向平面上并源自中心亮点上的同一点; 和(2)对于从中央亮点的各个子部分在各个方向传播的光具有相同的相对几何加权。 为了减少源自流动池中流动相关折射效应的噪声,流动池具有反射壁,并且大的收集镜将来自流动池的大锥体中的光入射到测量光电池中。 这个大锥体具有比进入流动池的光锥更宽的角度。

    Method and apparatus for reducing Schlieren noise in a liquid
chromatograph

    公开(公告)号:US4523097A

    公开(公告)日:1985-06-11

    申请号:US527954

    申请日:1983-08-31

    摘要: A beam of light falling within the range of 180 to 3,000 nanometers is transmitted through a flow cell in an optical compartment of an absorbance detector after warm up of the equipment while the eluant flows through the flow cell from a chromatographic column. The column extends upwardly from the absorbance detector into an air chamber having a volume of approximately 0.25 cubic foot formed with acrylic walls. Air flows from the absorbance detector under the power of a fan at approximately 10 cubic feet per minute upwardly through an air duct having a cross section of approximately 1.5 square inches to the top where it connects with the air chamber, the speed of the motor being adjustable until temperature varies less than one degree Celsius between the flow cell and the lower 10 centimeters of the column. Under these conditions Schlieren noise from the flow cell due to flow-induced thermo-optical effects is reduced.