FlexStream Specifications

Principle of Operation

  • Dilution of constant component vapor emission from permeation or diffusion tubes 
  • Delivery of precise, adjustable, low concentration dynamically blended gas mixtures. Trace concentrations - ppmv, ppbv, pptv 
  • Front panel touchscreen for oven temperature and dilution flow rate adjustment and standby, zero and span selection 
  • External PC monitoring and control via industry-standard Modbus RTU communications protocol and Ethernet or serial RS-232 connectivity 

Permeation Tube Oven 

  • High thermal mass oven with electronic PID control in Vertical orientation
  • Oven temperature range (heat only): 30-150 °C
  • NIST-traceable oven temperature 
  • Oven setpoint resolution and control: ±0.01 °C
  • Temperature digital indication and adjust via front panel
  • Temperature digital indication and adjust via computer interface
  • Over-temperature detection with audible alarm and oven power removal

Diluent Gas (customer-supplied)  

  • Uses inert, non-reactive, non-hazardous dry gas (nitrogen, zero air, argon, etc.) 
  • Mass flow controller subsystem is factory-calibrated in nitrogen; contact factory for calibration in other type gas
  • FlexSteam accepts a gas correction factor (GCF) for most gases to auto-adjust the dilution mass flow rate when a diluent gas other than nitrogen is used
  • Using the supplied FlexLink PC-based software, the mass flow controller subsystem can be easily calibrated with up to 10 points in other diluent gases (Customer supplies the flow standard)

Primary Dilution Mass Flow Controller 

  • Standard mass flow controller range: 0.25 to 5 l/min
  • Optional mass flow controller ranges available (0.5-10, 0.1-1, 0.1-0.5 l/min) 
  • Mass flow rate accuracy (with multi-point calibration):
  •  Lesser of ±1.5% reading and ±1% FS
  • Mass flow rate digital indication and control via front panel 
  • Mass flow rate digital indication and control via computer interface
  • Mass flow controller calibration method: piece-wise linear fit with up to 10 calibration points

Accepts Vapor Emissions from the Following Devices (A single oven can hold only one of the above tube types at a time)  

  • Liquid-filled disposable tubes up to 15 cm in length (maximum of 8 tubes) 
  • Liquid-filled high rate (LFH) permeation tubes (maximum of 1 tube) 
  • Factory pre-filled gas-fed permeation tubes (maximum of 1 tube) 
  • Diffusion tubes (maximum of 4 tubes)

Standard Component Flow Path  

  • Component contacts only glass, Teflon and stainless steel 
  • Glass permeation tube holder 
  • Suitable for reactive component gases

Optional Component Flow Path (specified at time of order)  

  • Heated output lines 
  • Stainless steel 
  • Electro-polished stainless steel 
  • Sulfinert-coated stainless steel 
  • Teflon only 
  • Teflon permeation tube holder

Standard Modes of Operation  

  • Standby (oven venting at approx 75 cc/min flow rate) 
  • Zero (with user-specified flow rate) 
  • Span-by-flow (with user-specified flow rate or concentration) 
  • Span-by-concentration (with user-specified target concentration) 
  • Purge 
  • Auto-calculates flow setpoint based on target concentration, tube emission rate and oven temperature 
  • Automatically updates touchscreen with up to 8 generated concentration values

Output Concentration Range  

  • Below 1 ppb to over 1000 ppm depending on tube emission rate and dilution flow rate; low ppb and ppt concentrations with secondary dilution
  • User selects units of ppm, ppb or ppt


  • Local interface - color touch screen display with virtual keypad 
  • Remote interfaces - Ethernet (standard) and serial RS-232 (standard) 
  • RS-232 conversion to RS-485 via customer-supplied converter (optional)
  • Communications Protocol Modbus RTU

PC-based Software

  • KIN-TEK FlexLink software CD shipped with FlexStream Base module 
  • FlexStream Labview Modbus driver on FlexLink CD 
  • LabView-based starter software with source provided upon request


  • Additional permeation ovens (via up to 5 FlexPM modules) 
  • Customer-refillable gas-fed permeation oven option (via FlexGF modules) 
  • Secondary diluition flow rate option (via FlexSD module): 0.5 to 5 l/min (other ranges available)
  • Overall output gas stream dilution ratio with both primary and secondary dilution: up to 10,000 to 1
  • Direct gas blending module option (via 491M-DGB) 
  • Humidified gas module option (contact factory for more information) 
  • Gas stream output Interface Module option via FlexIM module: ambient to 207 kPa (30 psig). (If FlexSD secondary dilution module is installed, subtract 69 kPa (10 psig))

Instrument Housing (specified when ordering)  

  • Carrying case (standard) 
  • Expansion chassis (optional); desktop or rack-mount, maximum 2 cases,  maximum 3 modules per case
  • Maximum 6 modules in a single FlexStream system: 

Power Requirements (specified when ordering)  

  • 115 VAC, 50/60 Hz, 2A 
  • 230 VAC, 50/60 Hz, 1A 

Dimensions and Weight  

  • Dimensions (Base module as packaged in carrying case):
  •  18.4 W x 34.3 H x 50.8 D cm3
  • Weight (Base module as packaged in carrying case): 12.2 kg   


  • European CE Mark (230 VAC, 50 Hz): FlexBase, FlexPM, FlexSD 
  • NRTL (site-specific) 
  • CSA (site-specific)

Speciality Applications (Please contact us)  

  • Special diluent (carrier) gases other than inert gases 
  • Trace moisture 
  • Chemical compatibility issues 
  • Heat tracing requirements