141A Baratron

General performance switches
The 141A Absolute Pressure Switch offers fast, accurate, and reliable protection for vacuum equipment and processes. Designed for applications where a DC signal output is not required, the 141A has relay outputs that are easily interfaced with alarms, valve actuators, computers, process controllers, and other protection devices.

Key features

  • Fully adjustable set point for flexibility
  • All-metal, all-welded Inconel and stainless steel construction for corrosion resistance
  • Fast response switching – 20 msec

Baratron Capacitance Manometer Technology

Capacitance manometers are electro-mechanical gauges that can measure both pressure and vacuum. The capacitance gauge translates a pressure-modulated movement in a thin diaphragm into an electrical signal proportional to the pressure. The pressure sensor is the thin diaphragm that is exposed to the pressure or vacuum being measured via the inlet tube. An electrode is mounted in the reference cavity behind the diaphragm. Pressure differences between the process and the reference cavity deflect the diaphragm slightly, changing the distance between it and the electrode. Variations in this distance produce variations in the capacitance between the diaphragm and the electrode creating an electrical signal that is proportional to the pressure change. Since differences in the capacitance signal are produced by physical changes within the manometer and not by changes in the gas properties, pressure measurements by the capacitance manometer are independent of the composition of the gas being measured.

Fully Adjustable Set Point

The high accuracy set point can be adjusted from from 0.2% to 100% of Full Scale for tripping the switches relay. An LED provides visual ”above set point” indication, and facilitates adjustment of the set point.

Inconel and Stainless Steel Construction

The dual electrode sensor is an all-metal, all-welded design, thus exposing only corrosion-resistant Inconel and stainless steel to the process gases.

Absolute Pressure Switching

The 141A and 142A pressure switches are referenced to vacuum for absolute pressure trip point switching. Applications for absolute pressure switches include soft pumping, gas box switching, and safety interlocks.

DPDT Relay

A double pole double throw relay rated at 2 amps @ 30 VDC or 1 amp @ 120 VAC resistive provides the set point switching. The relay is energized when pressure is above set point. Fail-safe operation provides for the relay to be energized when pressure is below set point.

KRISTIAN FLODSTRÖM Product specialist Vacuum technology 010-155 03 11