The Experts below are selected from a list of 18 Experts worldwide ranked by ideXlab platform

Qiao Shuang - One of the best experts on this subject based on the ideXlab platform.

Charles A. Bishop - One of the best experts on this subject based on the ideXlab platform.

  • 3 – Pressure Measurement
    Vacuum Deposition onto Webs Films and Foils, 2007
    Co-Authors: Charles A. Bishop
    Abstract:

    Publisher Summary As the range of vacuum used is widened, so are the number of types of Gauges that can be used to measure the vacuum achieved. This chapter discusses the various types of Gauges such as Bourdon Gauge, pirani and Thermocouple Gauges, cold cathode ionization Gauge, and hot cathode ionization Gauge. The main purpose of Bourdon Gauge is to check if the door is sufficiently closed and the pumps are pulling vacuum. If the Gauge does not show an immediate movement away from atmospheric pressure, it usually means that the door needs to be closed further. The accuracy of the Gauge is poor but adequate for the purpose. The backing lines and roughing Gauges require something more accurate when reaching a lower pressure than the capsule Gauges, for this purpose the Thermocouple Gauge and Pirani Gauge fits are used . The basis of cold-cathode ionization Gauge is to have an anode and a cathode within a magnetic field. It produces currents used to indicate pressure. Hot cathode-ionization Gauge uses a hot wire to produce electrons by thermionic emission. The electrons are attracted to an anode grid. The electrons in oscillating around the grid increase their chances of undergoing ionizing collisions. The ions that are produced are attracted to a third electrode producing a measurable current. The pressure is related to the ion current and the electron-emission current.

K. Shcheglov - One of the best experts on this subject based on the ideXlab platform.

  • Bulk micromachined vacuum sensor
    Proceedings of International Solid State Sensors and Actuators Conference (Transducers '97), 1997
    Co-Authors: R.c. Gutierrez, C.b. Stell, Vatche Vorperian, T.k. Tang, K. Shcheglov
    Abstract:

    In this paper, we present recent work on the fabrication and testing of a silicon bulk micromachined vacuum sensor. The fabrication process, electronics, and various modes of operation are described. The pressure sensitivity is demonstrated between 10/sup -6/ Torr and 10/sup -1/ Torr by "calibrating" against a Thermocouple Gauge, a capacitance manometer, a spinning rotor Gauge, and a hot cathode ionization Gauge. For the preferred mode of operation, the frequency dependence on temperature is 0.007 Hz//spl deg/C, the device is vibration insensitive, and has a measured intrinsic Q-factor above 100,000.

C.l.f. Woodcock - One of the best experts on this subject based on the ideXlab platform.

R.c. Gutierrez - One of the best experts on this subject based on the ideXlab platform.

  • Bulk micromachined vacuum sensor
    Proceedings of International Solid State Sensors and Actuators Conference (Transducers '97), 1997
    Co-Authors: R.c. Gutierrez, C.b. Stell, Vatche Vorperian, T.k. Tang, K. Shcheglov
    Abstract:

    In this paper, we present recent work on the fabrication and testing of a silicon bulk micromachined vacuum sensor. The fabrication process, electronics, and various modes of operation are described. The pressure sensitivity is demonstrated between 10/sup -6/ Torr and 10/sup -1/ Torr by "calibrating" against a Thermocouple Gauge, a capacitance manometer, a spinning rotor Gauge, and a hot cathode ionization Gauge. For the preferred mode of operation, the frequency dependence on temperature is 0.007 Hz//spl deg/C, the device is vibration insensitive, and has a measured intrinsic Q-factor above 100,000.