290 MKS Instruments Charge-Rate B/A Ion Gauge Controller

The MKS Instruments 290 Series Charge-Rate B/A Ion Gauge Controllers are compact, stable, general purpose, hot filament digital ion gauges. They are intended for use in vacuum systems operating at pressures from 10^-3 Torr to 10^-9 Torr.

The MKS Instruments 290 Series Charge-Rate B/A Ion Gauge Controllers feature both analog and digital design techniques which are patented. As a result of these unique ideas, the instrument becomes auto-ranging and adjustment free. Operation is easy and straightforward.

The Charge-Rate technique converts ion current from the B/A gauge tube into voltage pulses whose frequency is proportional to pressure and inversely proportional to emission current. A microprocessor based frequency counter measures the rate of these pulses and displays this information as pressure. The instrument is protected against common forms of abuse such as overpressure and short circuits. Emission current is automatically reduced at higher pressures to maintain accuracy.

As a standard feature, there are two fail safe alarm set points. Relay contacts representing the output of these two set points will be found on the rear panel connector (J202).

There are optional features to the basic 290 Series such as two tube select, and front panel sensitivity adjust.

A 37-pin type D connector is located on the rear panel. It carries BCD data associated with the display as well as various input and output control functions.