FAQs

The FLS110 is an analogue mass flow sensor, there isn’t an ASIC in the package. The FLS110 firmware, provided by Flusso, runs on a standard microcontroller in your product to deliver digital flow and differential pressure sensing solutions that you can tailor to your application needs.

For more detail please see Developing Your Flow Sensing Solution with FLS110. This document includes references to detailed technical notes covering mechanical and fluidic integration, hardware design, firmware customisation (using our SDK) and more.

The FLS110 senses mass flow but the firmware can provide readings on a mass flow or volumetric flow basis.

If you select the volumetric flow basis, you can have readings for volume flow, differential pressure or even airspeed which are optionally compensated for flow temperature and pressure. The flow pressure has to be provided by your host application, using a separate sensor in your system.

FLS110 solutions are based on system-level thinking AND calibration which has the advantage of taking care of all sources of variation within your product. It’s up to you to choose the degree of calibration to meet the accuracy requirements for your application.

There are three levels of calibration available:

• Zero-point offset correction – which is ideal if you need precision, linearity and repeatability, rather than absolute accuracy. It is always done in your production test and can also be done “in service” if your product can set system flow to be zero. For example, during a power-up sequence when the fan that generates your flow is turned off.
• Single-point calibration – achieves excellent accuracy over a sub-range of the full FLS110 span. This approach is particularly useful where you are trying to maintain a target flow rate or differential pressure within your application.
• Three-point calibration – using non-zero flows or differential pressures delivers excellent absolute accuracy across the full FLS110 span.

Typical indoor air is fine to pass through the sensor without filtration. Air with a higher loading of particulates or aerosol should be filtered before passing through the sensor.

The FLS110 works up to 90%RH non-condensing. Occasional condensation in the sensor will adversely affect readings but performance should return to normal once the sensor dries out.

A key advantage of an FLS110 solution is the system approach to calibration, where the effect of bends in the flow path leading to the sensor are taken into account. In any reasonable flow path design you will achieve accurate readings regardless of elbows, junctions and other features upstream of the FLS110.

Please see our technical note Mechanical and Fluidic Integration of the FLS110 (available from our customer portal) for further guidance.

In situations where a flow measurement is required, the FLS110 improves on using one or more pressure sensors because it offers:

• negligible zero‑point drift;
• greater accuracy and repeatability for low flow rates and differential pressures; and
• requires very little pressure drop in the system flow path.

With simple I²C commands or API calls, FLS110 standard firmware supports:

• mass flow, volumetric flow and differential pressure readings in units of your choice; and
• control over sampling rates and averaging of measurements.

We also provide a software development kit (SDK) to allow further customisation with our standard FLS110 firmware. For example, allowing you to change the I²C interface to SPI or UART, and to add application code.

For example: to control a pump or fan, to indicate when a filter has become clogged, or to perform a multitude of other application functions alongside controlling the FSL110 firmware and taking readings.

It’s also possible to port the FLS110 firmware to a microcontroller that is already within your system and running your application code. Contact Flusso for support with that approach.

Please see Developing Your Flow sensing Solution with FLS110 for more information and further references.

The FLS110 is made using a unique combination of standard semiconductor-MEMS manufacturing processes and materials by an automotive-qualified foundry.

Our suppliers manufacture and test billions of devices every year so they can produce millions of FLS110 devices every month, using a tiny fraction of their available capacity.

Our growing Technical Distributor network provides first line support and Flusso’s in‑house applications engineering team can also provide direct support for your design‑in..

Please see here to find the closest distributor in your region.