Buyer guide: FCI ST100 and Fox FT2A

New day, new buyer guide! Today we’ll review two formidable competitors in the thermal mass flow meter market, the FCI ST100 and the Fox FT2A. We’ll discuss features, outline capabilities, and help you study these products with your process in mind.

So, you ready to spend a few minutes of your time productively? Oh yeah!


Our first contender comes from Fluid Components International. Oh, that’s what FCI means! Yeah, yeah, I know. #slowlearner

Anyway, FCI has a lot of expertise in this arena, so let’s see what the ST100 brings to the picnic!


If you want seamless integration and on-board data loggers, then you’ll dig the ST100. And I liked this device even more when I saw its display. The optical touch buttons may take some practice, but cuddle up with this one and it’ll feel downright friendly after a while.

image of FCI ST100 mass thermal flow meter
Courtesy of


The FCI ST100 can measure the mass flow rate of a fluid, absolutely, and temperature as well. If you need anything more, then FCI has other models for pressure, dual element, and such.

The ST100, with its simple integration, allows a variety of analog and digital protocols: HART, PROFIBUS PA, and FOUNDATION Fieldbus (FF) H1. On the not-so-simple side, it has a built-in data logger! You won’t find that in most other devices on the market!

image of FCI ST100
Courtesy of

I also enjoyed FCI’s transparency about the device. Most brands won’t tell you their capacities, but FCI does. Naturally, these numbers may change, depending on your process. Anyway, the ST100 fits pipes 2.5 inches and larger and has a micro-SD with a two-gigabyte capacity. That means you can store around 21 million readings! Stunning, isn’t it?


So the ST100 is an amazing device with a clear form and transparent function. You get a ton of features in one device at a decent price. It also supports USB and Ethernet communication, which makes it even more technically sound.   

I’d say most of the other devices in this segment got owned by FCI ST100, and we all know why.

Fox FT2A

Next up, the company with the cool logo! Everyone I know loves this logo, so the marketing department surely deserves a good golf clap. 

Setting aside branding expertise, Fox has reigned over the thermal flow realm for more than two decades. So of course we had to talk about the badass on the block!

Image of Fox FT2A
Courtesy of

Now let’s take a look at the Fox FT2A and highlight the pros and cons of adding a Fox device to your application.


Fox rules the roost in technical prowess. Sure, the FT2A looks kinda boring, but do we care? Nope. Because this crew focuses on function over form, and this device can handily outperform other devices in the same segment.

It has plenty of features, but one of my favorites? The digital protocols. It has DeviceNet and Modbus TCP-IP! But no HART. Yeah, kinda weird. If you want that one, then you’ll have to switch to the FT3.

In accuracy, it gives one percent of reading and 0.2 percent of full scale for inline and insertion options. That makes it easy to use on pipes between 1.5 to 12 inches in diameter.   


Yes indeedy, it can measure mass flow. In fact, it’ll measure the flow rate, flow total, and temperature, then send you this data through whatever protocol you pick. It also gives you discrete input and output.

image of Fox Model FT2A
Courtesy of

The display is simple and navigation okay. It could use a better user experience, though – just a couple fancy features and and maybe a smidge of seamless integration.

UX aside, you should know that the FT2A won two awards in 2014, in the categories of flow control innovation and processing breakthrough products. Not bad, huh?


The FT2A has features to wow you, although I had trouble with the integration. I couldn’t find the General Station Description (GSD) file or any illustrations on how to set up the device using outsourced tools for the PROFIBUS protocol. Didn’t like that.

You’ll need proprietary software to set it up and the USB port to access the options, too. Come on, Fox! Every device supports FF and a data logger in this range. You could’ve done for the FT2A just like the FT3, right?

In a nutshell, the Fox FT2A shows off Fox’s 20 years of  technical experience. With some more digital protocols and user interface tweaks, it could’ve been the device everyone threw their money at!

Table of comparison

Here you can check out the devices side by side and see which wins your vote.


image of buyer guide FCI ST100 and Fox FT2A
Courtesy of Category FCI ST100 FOX FT2A Verdict
1 Unboxing nice display, clear features, but no intuitive setup
not pretty, but simple and easy to figure out
2 Supported protocols HART, FF, PROFIBUS PA, Modbus RS485 among others no FF, PROFIBUS PA, or HART, although you can get HART in the FT3  ST100
3 Flow elements FPC, FP, and S sensors, with a table of gas conditions and characteristics in the brochure PowerPro Sensor technology and an online tool to analyze your data and offer the best product for you
4 Gas and gas mixes FCI provides a big list to figure it out Fox offers comparison among the models, and the online tool has the gas list
5 General information and documentation good site, with general answers on device page and brochure PDF; smart, concise, and commendable could use a better web interface; doesn’t offer much on the PowerPro sensor ST100


Basically, these devices serve the same purpose for different audiences. They come up to scratch equally with their fancy features, effective builds, and efficient measurement. So plug in your process data, count your pennies, and pick one. You can hardly go wrong!

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