146B-AAAOM-1 MKS Instruments Cluster Gauge Vacuum Gauge Measurement and Control System

The MKS Instruments 146 Series Cluster Gauge Vacuum Gauge Measurement and Control System is a versatile, 1/2 rack instrument which can power and provide concurrent readouts for up to four different vacuum gauges, or a combination of gauges and flow controllers. The instrument can support capacitance manometers (4, 5, or 6 decade), Pirani, and ion gauges. A Dual Channel feature automatically switches from one gauge to another, thus providing the potential for a continuous pressure reading display from 10^-10 to 10³ Torr. The channel in the main display can automatically switch from a rough vacuum gauge to a high vacuum gauge during pumpdown or backfill. The 146 unit can accept a user-defined set point to operate a flow controller. If more than one flow controller is used, a Totaling feature allows one controller to control the total flow of all the controllers combined. With the optional Control board installed, the 146 unit can govern an upstream solenoid valve, a downstream throttle valve, or one or more ratio controllers in a closed-loop pressure control system.

The 146 unit features four default recipes, each with an individual set point, phase lead, and gain setting. The recipes can easily be customized to meet the needs of different applications. By using the keyboard on the front panel, operators can: set alarm relay parameters, display pressure or leakage readings, choose display units (Torr, Pascal, mbar), and configure communication data. Control parameters such as base, lead, gain, integral, softstart, and start can also be adjusted through the front panel. Gauges can be zeroed and spanned individually, or cross-calibrated for span. There is an automatic ion gauge powerdown at high pressures, and a sensor powerdown for cryo-pump regeneration. The non-volatile memory stores all parameter entry values as well as sensor data such as capacitance manometer zero correction, and HPS Pirani spans. Diagnostic tests are included for basic troubleshooting.

The 146 instrument has a front panel window with a 4 1/2 digit main display, and three 2 1/2 digit displays. The LCD window is backlit with an electro-luminescent lamp, and has an automatic one-hour timeout. Although the LCD is readable without backlighting, any keystroke reilluminates the backlight in addition to erforming its usual function. All commands can be activated through the front panel, or the unit can be controlled via an interface with a computer through an RS-232 serial communication link. A front panel lockout feature disables command control through the front panel (except for the [QUIET/CANCEL] key). The 146 unit front panel lockout commands are entered through the available digital control lines or RS-232 messages.