9861 Series High Temperature Mass Flow Controllers & Meters

Improve high temperature flow control accuracy and efficiency.
Models 9861

Engineered for the challenging conditions associated with high temperature delivery of condensable precursors and dopants, the 9861 Series high temperature thermal mass flow controllers and meters from Brooks Instrument feature a high purity, high leak integrity metal flow path ensuring compatibility with all process gases and vapors. The patented IsoSensor™ is a high stability flow sensor compatible with the elevated environmental temperatures found in heated gas lines and baking systems. The ultra-low drift performance of the IsoSensor™ reduces the need for frequent re-zeroing and recalibration typical in high temperature applications.



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9861 Series Data Sheet


  • Ultra-stable patented IsoSensor™ flow measurement sensor
  • Ultra-high purity flow path
  • Remote electronics come standard with two analog electrical connectors
  • Digital measurement and control architecture


  • High stability sensor delivers superior uptime, reducing maintenance and lowering total cost of ownership
  • All-metal wetted flow path ensures integrity and purity of gas/vapor
  • Included 20 pin card edge and a 9 or 15 pin “D” connector enables standardization and reduces inventory
  • Enhanced accuracy and process control


  • Optical fiber manufacturing - MCVD
  • Silicon semiconductor device fabrication processes
Product Type
Mass Flow Controller

Highest Flow Accuracy

Highest Operating Temperature

Digital Communication

Flow Range (Full Scale Capacity)
10 slm (N2 equivalent)

1% of SP@ 35 - 100% FS

0.35% of FS @ <35% FS

<±0.15% FS

±0.5% FS (included in accuracy)

Response Time

<1 sec to within 2% of SP (per SEMI E17-91)

Zero Stability
<±0.5% FS per °C
Seal Material
Level of Purity / Surface Finish
4 μ inch Ra
Wetted Materials

316L SS/ KM-45/ 304 SS/ MO+

Valve Options

Normally Closed

Meter (no valve)

Max Temperature
Differential Pressure Range

1.33 - 350 kPa (10 torr - 50 psia)

*Contact Brooks Technical Support for more information.

Max Pressure

620 kPa (90 psi)

Leak Integrity
1x10-10 atm cc/sec He

Diagnostic Capability
Analog Communication

0-5 Vdc

Digital Communication

RS485 L-Protocol (via dual RJ11 ports)

Electrical Connection

Analog via 9- or 15-Pin "D" connector & 20 Pin Card Edge connector

Power Supply / Consumption

Controller (Analog & RS-485L): 5 Watts max @ ±15 Vdc (160 mA max)

Meter (Analog): 5 Watts max @ ±15 Vdc (50 mA max)

Flow Range (Full Scale Capacity) 3 sccm - 10 slm (N2 equivalent)
Surface Finish 4µ inch Ra

±1% SP @ 35 - 100% FS

±0.35% FS @ <35% FS

Repeatability < ±0.15% FS
Response Time

1 sec to within 2% of SP (per SEMI E17-91)


Analog Communication

0-5 Vdc

Digital Communication

RS485L Protocol


Filename File Type Documents By Language
Data Sheet pdf English
Installation & Operation Manual pdf English

Use the following guide (model code information from data sheet) to translate the CAD configurations available below. If you need assistance or can’t find what you’re looking for, please contact Applications Engineering or your local Brooks Instrument representative.

Example: 9861 - 4R - U

Meter Series
Process Connection
 9861 4R - 1/4” VCR
T - 9 pin D connector & 20 pin card edge connector & dual RJ11 ports, 0-5 VDC
  3R - 3/8” VCR
U - 15 pin D connector & 20 pin card edge connector & dual RJ11 ports, 0-5 VDC
Filename File Type
9861-4R-U STEP
9861-4R-U IGS
9861-4R-U DXF