Compare Model Drawings, CAD & Specs Type Pressure Range Full Scale Fitting Type Connector Relay Mode Availability Price
$480
3 Weeks
Vacuum Pressure Switch 10 Torr 4 VCR male 9-pin male D subminiature Energizes below set point
3 Weeks
$480
3 Weeks
Vacuum Pressure Switch 10 Torr 4 VCR female 2 ft. Flying Leads Energizes below set point
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Vacuum Pressure Switch 1000 Torr NW16 ISO-KF 9-pin male D subminiature Energizes above set point
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Product Options

Description
  41b/51b baratron pressure switch 41B Differential Pressure Switch, 10 - 26,000 Torr, Single-End, 41B Series

Specifications

  • Type
    Baratron® Vacuum Pressure Switch
  • Measurement Type
    Differential
  • Configuration
    Single-Ended
  • Accuracy
    ±0.5% of Full Scale (± temperature coefficient)
  • Trip Point Range
    5% to 100% of Full Scale
  • Trip Point Dead Band
    ±3% of Full Scale
  • Response Time
    <20 msec
  • Internal Volume
    3.3 cc
  • Temperature Coefficient
    ±0.07% of Full Scale/°C
  • Materials Exposed to Process Gases
    Inconel and 316L stainless steel
  • Overpressure
    2 x Full Scale or 45 psia, whichever is greater
  • Outputs
    Electromechanical relay - SPDT (isolated) contacts rated up to 1 Amp @ 30 VDC resistive.
  • Power Requirements
    20 - 30 VDC
  • Ambient Operating Temperature
    0 - 50°C
  • Compliance
    CE Compliant to EMC Directive 2004/108/EC

Features

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.

Capacitance manometer sensor schematic showing the internal components

Referenced to Atmospheric Pressure

The 41B and 42B models are referenced to atmospheric pressure. The 41B/42B switches are often used to ensure a loadlock pressure has equilibrated to local atmospheric pressure before opening the door. The trip point on MKS’ atmospheric switches can be set to trip above, below (reverse calibration), or exactly at current atmospheric pressure.

Factory Set Trip Point

The relay trip point is factory set from 5% to 100% of the Full Scale pressure range. This means there is no need for personnel to adjust the set point and no safety concerns from an erroneously adjusted set point.

Fail-Safe Relay Operation

The relay mode on 41B, 42B, 51B, and 52B switches can be set to either energize above or below the set point. If the unit loses power, the relay switches to the Normally Closed position. The user can indicate whether the Normally Closed position is above or below the set point. Using Energize Above the set point as an example, the relay is in the Normally Open position when the pressure is higher than the trip point and Normally Closed when the pressure is below the trip point. The scenario is reversed for Energize Below the set point option. In vacuum systems, the fail-safe operation is if the system loses power causing the relay to de-energize, the relay is in the same state as the high pressure condition. Therefore, most vacuum systems require the relay energize with pressure decreasing or below the set point.

The 41B, 42B, 51B and 52B Vacuum and Atmospheric Pressure Switches provide increased accuracy over mechanical type switches, thereby providing tighter control and repeatability of process, improving throughput and yield.

9-pin Type “D” Pinouts

Pin Description
1 Power Return (-)
2 Power Input (+)
3 Relay NO Contact
4 Relay Common
5 Relay NC Contact
6 Unused
7 Unused
8 Unused
9 Chassis Ground

Flying Lead Wiring

Wire Description
Red Power Input (+)
Black Power Return (-)
Green Relay NO Contact
White Relay Common
Orange Relay NC Contact
Bare Wire Chassis Ground

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