Coaxial BNC Feedthroughs and Components

The 'Bayonet Neill-Concelman' Connector, usually referred to as a BNC coaxial connection, is commonly used in conjunction with low noise 50-ohm instrumentation lines.  Accu-Glass Products' coaxial BNC instrumentation feedthroughs are constructed with either floating shields or grounded shields.

Floating shields provide two concentric conductors: one outer metal tube or shield conductor concentric with, and enclosing, a cylindrical center conductor.  Both electrical paths are electrically isolated from the vacuum flange.

Grounded shields provide only one electrical path that is electrically isolated from the vacuum flange.  With grounded shields, the shield and vacuum flange are electrically common.

Ultrahigh (UHV) compatible coaxial cable assemblies are available to meet the needs of most in-vacuum, low noise instrumentation cable applications.  The vacuum side of a grounded and floating BNC feedthrough consists of a 0.094 inch (2.4mm) diameter conductor pin that mates perfectly with Accu-Glass Products' grounded, or floating Accufast™ connector interface.

mating warning diagram on differences between BNC and MHV feedthroughs

Section (Layout)
Left Column Content
Callout Image
BNC Coaxial Feedthroughs
Image Callout
UHV female cable 4 assembly, 110180, stainless steel Accufast™ connector and Kapton® insulated coaxial cable
94
283
Air-service female cable (4) assembly, 110185, connector and cable
242
112
UHV BNC Coaxial Feedthroughs
389
119
Text

BNC Coaxial Interface

The 'Bayonet Neill-Concelman' connector, referred to as a BNC coaxial connection, is commonly used in conjunction with low noise 50-ohm instrumentation signal lines. BNC coaxial feedthroughs are constructed in both grounded and floating shield configurations. Floating shield types provide two concentric conductor paths: an outer metal conductor tube (shield) concentric with, and enclosing, a cylindrical center conductor pin. Both paths are electrically isolated from each other and a mounting flange. Grounded shield BNCs provide only one path that's electrically isolated from the flange, where grounded shield and flange are electrically common. Vacuum side of single-ended grounded and floating BNC feedthroughs have a 0.094 inch (2.4-mm) diameter conductor pin that mates with grounded or floating AccuFast™ connectors.

BNC / MHV Interface Comparison

 

Glow Discharge Graph
Right Column Content
Text

Features

  • BNC Coaxial Interface
  • Grounded and Floating Shield
  • Single and Double Ended configurations
  • Kapton® insulated 50-Ohm cable
  • High temperature rated to 250°C
  • UHV compatible construction
  • Conflat® and ISO KF compatible mounts
  • Air service cables / connectors
  • Custom solutions on request
     

Specifications

Electrical 
Voltage 1, Maximum 
   Grounded Shield500 VDC
   Floating Shield2,500 VDC
   Current, Max @ 20°C3 A
Material 
Shell304 Ss
Pin / Conductor304 Ss
Insulation, CeramicAlumina
Connector, Vacuum 2 
   AccuFast™PEEK / Ss
   BNCPEEK / Brass
   SMAPEEK / Brass
   User-EndPEEK / BeCu
Connector, AirComposite
Cable InsulationKapton®
Vacuum Range 
UHV, Ultrahigh vacuum1x10E-10 Torr
HV, High vacuum1x10E-8 Torr
Temperature Range 
Feedthrough-200 to 250°C
Flange, Conflat®450°C
Flange, ISO150°C
Connector / Cable, Air165°C
Connector / Cable, UHV PEEK250°C
Thermal Gradient, Maximum25°C/minute
Notes 
  1. Electrical ratings are maximum test values, with feedthrough's vacuum side at ≤ 1x10E-4 Torr. Feedthroughs are intended for instrumentation applications carrying low level signal voltage and current.
  2. PEEK is a polyether ether ketone thermoplastic.
  3. Overall assembly ratings must be adjusted to that of its lowest rated component. For cryogenic service, the lowest recommended temperature is -200°C
  4. Connectors and cables are not included with feedthrough and must be purchased separately.
Subscribe to BNC Coaxial