Downloads and Instructions for Your Liquid Flow Meter Kit

Thank you for being interested in our liquid flow sensor solutions! Below you will find all necessary documents as well as useful information regarding the evaluation of your liquid flow sensor. In case of further questions please contact our technical customer support team under www.sensirion.com/contact.

General Information:

• The sensor relies on a thermal measurement principle. Therefore it is sensitive to the thermodynamic properties of the fluid. For details see "CMOSens® for Liquid Flow Meters".
• Sensirion Liquid Flow Meters are 100% factory calibrated, typically for H₂O and/or IPA. However, your Liquid Flow Meter can be used to measure other fluids as well by choosing the calibration field most closely matching your fluid. Contact Sensirion if you want to use much different fluids in terms of thermal properties.
• Please see your data sheet for the specific pin-out of your sensor type.
• There are additional operating guidelines and application notes available which will be send to you on request (e.g. on I²C, installation guidelines, ...).
• Select „Liquid Flow Sensor (SF06 Chip)“ for the LD20 series and select „Liquid Flow Sensor (SF04 Chip)“ for all others.
• When choosing the COM Port Settings to start the Sensirion Viewer Software select a COM port so that “USB Serial Port” appears next to your COM port setting. It is a PC dependent setting and no general one.

Handling Instructions:

• Avoid strong mechanical shocks that could dislodge internal components or compromise the fluid seals.
• The maximum flow ranges of the sensor are specified such to achieve a laminar flow at the position of the micro thermal chip. Use tubing and fluidic connection material with at least the same inner diameter as the one of the capillary.
• Start testing the sensor horizontally mounted. This is the orientation it has been calibrated in.

Cleaning Instructions:

• After ending your measurements, make sure to always store the sensor's flow channel clean and dry in order to maintain a high level of performance. This avoids the growth of a biofilm or other deposits which will impact the sensor's reading the next time. To do so, always drain the fluid, flush with cleaning agent (deionized water first, then acetone, and finally IPA) and blow out with air or allow to air dry. Do not use acetone for cleaning the sensors of the LD20 series. Its wetted materials are not compatible with acetone.
• In case you encounter a drifting behavior of the sensor, it might be due to deposits inside the capillary. Flush the sensor with acetone or IPA (maybe several times) or try storing it overnight with the sensor's flow channel filled with acetone. You can even run bleach to remove very sticky biofilms. Never mechanically clean the sensor's fluidic channel.