SFAH-0.1B-G18FS-PNLK-PNVBA-M8 Festo Flow Sensor

Technical Overview

A high-performance thermal flow sensor designed for precise bidirectional measurement of compressed air and nitrogen. The SFAH features an integrated multi-colour illuminated LCD display and supports IO-Link communication for advanced diagnostics and parameterization. It provides versatile output options including switchable PNP/NPN and selectable analog signals (0-10V, 4-20mA, 1-5V), making it suitable for a wide range of industrial automation applications requiring mass and volumetric flow monitoring.

Key Features

Bidirectional flow measurement
Thermal measuring principle via heat transfer
Multi-colour illuminated LCD display
IO-Link® communication protocol supported
Switchable output signals (PNP/NPN)
Configurable analog outputs (0-10 V, 4-20 mA, 1-5 V)
Multiple switching functions: Window and threshold value comparators
Short circuit and overload protection
Cleanroom suitability Class 4 according to ISO 14644-1
RoHS-compliant materials

Technical Specification Matrix

Parameter	Value
Symbol	00995794
Approval	RCM trademark c UL us listed (OL)
CE mark	To EU EMC Directive In accordance with EU RoHS Directive
UKCA marking	To UK RoHS instructions
Certificate issuing authority	UL E322346
Note on materials	RoHS-compliant
Measured variable	Mass flow rate, Volumetric flow rate
Flow direction	Bidirectional
Measuring principle	Thermal
Measurement method	Heat transfer
Start value for flow rate measuring range	0.002 l/min
End value for flow rate measuring range	0.1 l/min
Operating pressure	-0.9 bar ... 10 bar
Operating medium	Compressed air to ISO 8573-1:2010 [6:4:4], Nitrogen
Media temperature	0 °C ... 50 °C
Ambient temperature	0 °C ... 50 °C
Nominal temperature	23 °C
Accuracy of flow rate	± (2% o.m.v. + 1% FS)
Repetition accuracy offset in ± %FS	0.2 %FS
Repetition accuracy span in ± %FS	0.8 %FS
Temperature coefficient span in ± %FS/K	Typ. 0.15%FS/K
Pressure influence span in ± %FS/bar	1 %FS/b.
Switching output	2 x PNP or 2 x NPN, switchable
Switching function	Window comparator, Threshold value comparator, Auto difference monitoring
Switching element function	N/C or N/O contact, switchable
Max. output current	100 mA
Analogue output	0 - 10 V, 4 - 20 mA, 1 - 5 V
Flow characteristic curve start value	-0.1 l/min
Flow characteristic curve end value	0.1 l/min
Max. load resistance current output	500 Ohm
Min. load resistance voltage output	20 kOhm
Short circuit current rating	yes
Overload protection	Available
Protocol	IO-Link®
IO-Link, Protocol version	Device V 1.1
IO-Link, Profile	Smart sensor profile
IO-Link, Function classes	Binary data channel (BDC), Process data variable (PDV), Identification, Diagnostics, Teach channel
IO-Link, communication mode	COM2 (38.4 kBaud)
IO-Link, SIO-Mode support	Yes
IO-Link, Port class	A
IO-Link, Process data length IN	3 bytes
IO-Link, Process data content IN	1 bit BDC (volume monitoring), 14 bit PDV (measured flow value), 2 bit BDC (flow monitoring)
IO-Link, Service data IN	32-bit volume/mass measurement
IO-Link, Min. cycle time	4 ms
IO-Link, Data storage required	<500 Byte
Operational voltage range DC	22 V ... 26 V
No-load supply current	≤25 mA
Reverse polarity protection	For all electrical connections
Electrical connection 1, connection type	Plugs
Electrical connection 1, connector system	M8x1, A-coded, to EN 61076-2-104
Electrical connection 1, number of connections/cores	4
Electrical connection 1, type of mounting	Not rotatable
Electrical connection 1, compatible type of mounting	Compatible with latching lock, Compatible with rotatable screw-type lock
Electrical connection 1, connection pattern	00991171
Type of mounting	With accessories
Mounting position	optional
Pneumatic connection	Female thread G1/8
Pneumatic connection, outlet direction	Straight
Product weight	90 g
Material housing	PA-reinforced
Material in contact with the medium	Silicon, Silicon nitride, High-alloy stainless steel
Display type	Illuminated LCD, multi-colour
Displayable units	g, g/min, l, l/h, l/min, scft, scft/h
Setting options	IO-Link®, Teach-in, Via display and keys
Protection against tampering	IO-Link PIN code
Degree of protection	IP40
Pressure drop	<5 mbar
Protection class	III
Corrosion resistance class CRC	2 - Moderate corrosion stress
LABS (PWIS) conformity	VDMA24364-B2-L
Cleanroom suitability	Class 4 according to ISO 14644-1
Pollution degree	3

Industrial Applications

1. Semiconductor Wafer Vacuum Grip Verification

Utilizing the flow sensor in a semiconductor cleanroom environment to monitor precise vacuum flow during robotic handling of fragile wafers. The sensor's bidirectional measurement and ability to detect flow down to 0.002 l/min identify micro-leaks indicative of a cracked wafer or an improper suction grip, sending instant diagnostic feedback to the PLC via IO-Link.

Problem Solved

Prevents dropping expensive semiconductor wafers or processing damaged wafers by detecting microscopic vacuum leaks instantly during automated pick-and-place operations.

Cleanroom Class 4 according to ISO 14644-1Operating pressure -0.9 bar ... 10 barStart value 0.002 l/minIO-Link Smart sensor profileBidirectional flow direction

2. Micro-Leak Testing in Medical Device Assembly

Integrating the flow sensor into quality control end-of-line test stations for miniature medical devices, such as catheters and micro-valves. By injecting compressed air or nitrogen and monitoring the precise mass flow rate, the sensor uses its built-in window comparator switching function to flag defective, leaking parts in real-time.

Problem Solved

Replaces slow pressure-decay leak testing methods with instantaneous flow-based micro-leak detection, accelerating production throughput while ensuring life-critical medical-grade seal integrity.

Window comparator switching functionNitrogen operating mediumEnd value for flow rate 0.1 l/minMin. cycle time 4 msVolumetric flow rate measured variable

3. Precision Nitrogen Blanketing for Optical Assembly

Employing the flow sensor to regulate an ultra-low, continuous flow of nitrogen gas over sensitive optical lenses to prevent oxidation. The LABS (PWIS) compliant construction guarantees no paint-wetting impairment substances outgas onto the optics, while the analog output ensures the flow stays precisely within the 0.1 l/min limit to prevent air turbulence.

Problem Solved

Eliminates the risk of moisture or oxidation damage to precision optics without causing disruptive gas turbulence or wasting expensive inert gases, ensuring strict cleanliness standards are met.

LABS (PWIS) conformity VDMA24364-B2-LAnalogue output 4 - 20 mAAccuracy of flow rate ± (2% o.m.v. + 1% FS)Nitrogen purgingIP40 Degree of protection