SFM4100 Series
Low-cost Digital Mass Flow Meter for Gases
Accuracy 3% m.v.
2
Digital output (I C)
Multigas option available
Calibrated and temperature compensated
Excellent long-term stability
Downmount or legris carstick fittings
Product Summary
The SFM4100 gas flow meter series is designed as a The outstanding performance of these sensors is based
versatile OEM gas flow meter for demanding volume on Sensirions patented CMOSens sensor technology,
applications. which combines the sensor element, signal processing
and digital calibration on a single microchip. The mass
The SFM4100 is designed to measure Air and non-
flow is measured by a thermal method on the MEMS
aggressive gases with excellent accuracy over a large
sensor element. Compared to other thermal mass flow
dynamic range. Mass flows ranges up to 20 slm are
sensors (MEMS, hotwire or capillary type) the SFM4100
available. The SFM4100 series operates with supply
features an extended dynamic range, higher long-term
voltage 5-9 VDC and through its digital I2C interface it can
stability, and improved repeatability.
be easily embedded into a microprocessor environment.
The sturdy design of the SFM4100 sensor allows for The well-proven CMOS technology is perfectly suited for
operation pressures up to 10 barg. The flow signal is high-quality mass production and is the ideal choice for
internally lineralized and temperature compensated. demanding and cost-sensitive OEM applications.
Applications Sensor chip
Medical (e.g. respiratory care, anesthesia) The SFM4100 series features a fourth-generation silicon
Analytical Instruments sensor chip called SF04. In addition to a thermal mass
Leak testing flow sensor element, the chip contains an amplifier, A/D
Process automation converter, EEPROM memory, digital signal processing
circuitry, and interface. The highly sensitive chip is
Connection diagram
particularly sensitive at lowest flows, giving the SFM4100
sensor its large dynamic range.
VDD
VDD=3.5-9V
SFM4100 OEM options
VLS=2.9-5.5V
C
A variety of custom options such as other analog output,
SDA
different gases, flow ranges, multigas calibration can be
(master)
implemented for high-volume OEM applications
SCK
GND (>1000pc/y). Ask us for more information.
SFM4100 series with bidirectional digital communication
2
(I C bus)
www.sensirion.com Version 1.3 January 2013 1/9
1.3 Materials
1. Sensor Performance
Parameter SFM4100 Series
Wetted materials
1.1 Physical specifications Si, Si N , SiOx, Gold, Viton , Epoxy, PA-
3 4
1
Parameter SFM4100 12, Stainless Steel, Nickel Plated Brass,
Nylon, Nitrile, coated Aluminium,
2
Measurement range 0-20 slm
Oxygenoex
Calibration available Air, N2, O2, N2O, Ar or CO2
RoHS fully RoHS compliant
12 bits preset
Resolution
(for 916 bits see documentation)
3,4
Zero point accuracy 0.03 slm
2. Electrical Specifications
0.15% of full scale or 3% of reading,
3,4
Accuracy
whichever is bigger
0.25% of reading or 5 sccm whichever 2.1 Power supply
Span repeatability
is bigger
The SFM4100 series sensors require a supply voltage
Offset shift due to
2 sccm / C (VDD) between 3.5V and 9 V. For the power supply of the
temperature variation
level shifter (VLS) a voltage between 2.9V and 5.5V is
Span shift due to
required. Please be aware that the VLS must be the same
< 0.1% of reading per C
temperature variation
as the voltage of SCK.
Offset stability < 0.01 slm/year
Pressure drop at full
2.2 Electrical characteristics
<25mbar
flow
Parameter SFM4100
4.6 ms @ 12-bit resolution
Supply voltage 3.5 9.0 VDD
Response time (See documentation for response times with
7
other resolutions, e.g. 1.3 ms with 10 bits)
Level Shifter Supply 2.9 -5.5 VLS
Warm-up time for first Max. 500ms
Current drain < 12.5 mA typical in operation
reliable measurement in general 50 ms
2
Interface Digital 2-wire interface (I C)
1
Unless otherwise noted, all sensor specifications are at 23C and
Bus clock frequency SCL: 100 kHz typical
absolute pressure = 4,8 bar.
2
Reference conditions for standard liters per minute slm: 20C,
Air: 1 (0000001)
1013mbar; sccm denotes standard cubic centimeters per minute
O2: 2 (0000010)
2
3 Default I C address
includes repeatability and hysteresis.
CO : 3 (0000011)
2
4
per gas type
The zero-point accuracy and span accuracy are independent
N2O: 4 (0000100)
uncertainties and add according to the principles of error propagation.
Ar: 5 (0000101)
Flow in sccm = value received 1
Flow output signal
Flow in slm = value received / 1000
1.2 Ambient conditions
7
Same voltage as the communication level of the P is required.
Parameter SFM4100 Series
5
Noncorrosive gases and gas
Media compatibility
mixtures
6
Limited media compatibility corrosive Gases
5
Calibrated temperature range 0 C to +50 C
Operating temperature -20 C to +80 C
5
Storage temperature -40 C to +80 C
Operating Pressure Range 0-6 bar gauge
Position sensitivity Use flow horizontally, electronic
connector up
5
Contact Sensirion for information about other gases, wider calibrated
temperature ranges and higher storage temperatures.
6
For a limited time period, depending on chemical. Not recommended.
www.sensirion.com Version 1.3 January 2013 2/9