5861I is a Brooks Instrument Model 5861i thermal mass flowmeter for gas mass-flow measurement. Official Brooks documentation identifies the 5861i as a mass flow measurement device with a flow sensor and integral electronic signal conditioner, used in semiconductor and other gas-handling applications. Exact gas calibration, full-scale range, fittings, output option, and service suitability must be verified from the physical unit label and calibration records
Unit-specific configuration
Observed configuration
Historical listing records identify this part as Air at 80 SLPM. Exact gas, range, fittings, valve configuration, and communication interface must be verified from the physical unit label.
Configurations vary. Verify the exact unit before choosing a replacement.
Application classSemiconductor/high-purity gas delivery
CategoryFlow Control
Specifications
Identification
Device type
Thermal mass flow meter for gases
Series family
Brooks 5800E Series elastomer-sealed analog gas mass flow controllers and meters
Model family
Brooks Instrument Model 5861i mass flowmeter
Part identifier
5861I / 5861i
Official manual identity
Brooks Model 5861i Mass Flowmeter installation and operation manual X-TMF-5861i-MFM-eng, part number 541B111AAG, November 2008
Function
Primary function
Measures gas mass flow and provides an electrical flow output signal for indicating or recording
Internal measurement architecture
Official manual describes the 5861i as a flow sensor with an integral electronic signal conditioner
Flow
Standard full-scale range
10 slpm to 100 slpm nitrogen equivalent, with up to 200 slpm hydrogen listed in the official 5861i manual
Reference conditions
SEMI standard conditions of 0 C and 101.3 kPa / 760 Torr
Performance
Accuracy
+/-1% full scale including linearity at calibration conditions
Repeatability
0.25% of rate
Response time
Less than 6 seconds to within 2% of full-scale final value for a 0 to 100% flow step
Pressure
Working pressure
1500 psi / 10.34 MPa maximum in the official 5861i manual; 5800E data sheet lists 1500 psi / 103 bar for the 5851/5861 model row
Environmental
Operating temperature
5 C to 65 C / 40 F to 150 F
Non-operating temperature
-25 C to 100 C / -13 F to 212 F
Electrical
Power requirement
+15 to +28 Vdc at 90 mA; 2.5 watts maximum power consumption at 28 volts
Output signal
0-5 Vdc into 2000 ohms or greater, with 3 mV maximum ripple
Electrical connector
D-type 15-pin male DA-15P connector
Mechanical
Process connection context
Official 5861i documentation lists 1/4 inch compression, 1/4 inch VCO, 1/4 inch VCR, 3/8 inch compression, and 3/8 inch or 1/2 inch VCO/VCR dimensional connection contexts; actual fitting is configuration-specific
Installation
Mounting orientation
Official manual states the 5861i can be installed in any position, but orientations other than the original factory calibration may create up to a +/-0.5% full-scale shift after re-zeroing
Recommended inlet filtration
Official manual recommends a 15 micron filter for 10-30 slpm maximum flow and a 30 micron filter above 30 slpm
Materials
Primary wetted materials context
5800E data sheet lists 316L stainless steel, high alloy stainless steel, Viton fluoroelastomers, Buna-N, Kalrez, and Teflon as primary wetted materials for the series
Leak integrity
External leak integrity context
5800E data sheet lists 1 x 10^-9 atm cc/sec helium external leak integrity for the series
Configuration
Configured-unit rule
Gas calibration, full-scale range, reference conditions, fitting style, output option, connector wiring, and calibration history vary by configured model code and physical nameplate
Applications
Application domain
Gas mass-flow measurement in semiconductor, laboratory, analytical, life-science, process, and industrial gas-handling systems
Compatibility
Verification boundary
Do not assume interchangeability with 5851 controller models, 5861E variants, SLA5861 models, or any configured sibling code without checking gas, range, fittings, output, wiring, pressure rating, and calibration
