Datasheet Liquid Flow Sensor SLI0 pages

SLI Liquid Flow Meter

Media Isolated Microfluidic Flow Meter
Totally Non Invasive
Digital RS485 Interface
High Speed Flow Measurement
1

Introduction SLI Flow Meter

The SLI Liquid Flow Meter series enables fast, non-invasive measurements of very low liquid flow in the ml-range.
Excellent chemical resistance and bio-compatibility are ensured: The flow path of the SLI Liquid Flow Meters is formed
by a simple, straight glass capillary. The Swiss made, non-invasive sensors are based on Sensirion’s patented
CMOSens® Technology (US Patent 6,813,944 B2). The fourth generation MEMS sensors combine a thermal high
precision sensor element with amplification circuits and digital intelligence for linearization and temperature
compensation on one single microchip – the products core element.

2

Overview of Key Specifications

Table 1: Specifications of SLI for H2O
Parameter
Maximum Flow Rate
Lowest Calibrated Flow (LCF)
Accuracy above LCF
Operating Temperature
Digital Interface
Power Supply DC, VDD
Overpressure Resistance

(all data for medium H2O, 20°C, 1 barabs unless otherwise noted)

SLI-0430

SLI-1000

SLI-2000

50
2
5.0

1000
40
5.0
+10 … +50
RS485
4.5 – 5.5
15

5000
200
5.0

50

µl/min
µl/min
% of m.v. a
°C
V
bar

5

Table 2: Specifications of SLI for hydrocarbon based liquids (comparable with oil, solvents, fuel, alcohol)
(all data for medium Isopropyl Alcohol, 20°C, 1 barabs unless otherwise noted)
SLI-0430
SLI-1000
SLI-2000
Parameter
Maximum Flow Rate
(depend on specific liquid type)
Lowest Calibrated Flow (LCF)
Accuracy above LCF

3

0.5

10

80 (120 b)

ml/min

0.025
20

0.5
20

4
20

ml/min
% of m.v.a

Output Signals

The flow meter offers a RS485 interface option with bus capability. This interface is embedded in the RS485 Sensor
Cable that comes together with the sensor if ordered accordingly.
For the detailed specifications of the RS485 communication interface, refer to the documents for the RS485 Sensor
Cable. It is not possible to replace the Sensor Cable with a standard cable.
The SLI Flow Meter can be switched to two different measurement modes by using RS485 commands:
measurement mode with calibration for bi-directional flow measurement of water
measurement mode for hydrocarbon based liquids, calibrated for Isopropyl Alcohol (IPA)
a
b

Measured value
Extension possible on request

www.sensirion.com

Version 8, August 2012

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