Fuel Flow Monitoring Equipment - Why So Expensive?

The FlowScan thread reminded me of a question I've always had, but I didn't want to hijack that thread.

Why are these sensors so expensive? OK, I get that the computers to tally up the pulses and spit out N2K require a lot of design and coding work, even thought the parts are dirt cheap.

But surely flow sensors which do nothing but send out a pulse shouldn't cost more than a few bucks.

These are the kinds of things I ponder when I'm stuck inside on a snowy day...

No demand and no competition. Other words, Supply and Demand, no demand so very little supply.

tiltrider1 said:

No demand and no competition. Other words, Supply and Demand, no demand so very little supply.

Click to expand...

I had just been thinking about the same thing over the last week (and bought a system last night!) but you have it in one. Stand alone systems can't be a huge business, especially since most new engines come with this built in.

stevemitchell said:

Stand alone systems can't be a huge business, especially since most new engines come with this built in.

Click to expand...

Good point, I'd forgotten that. I always figured that's why FlowScan went out of business in the first place.

So I guess there's no market for a fairly priced monitor which uses inexpensive off-the-shelf sensors. Another business plan down the tubes!

CaptTom said:

Good point, I'd forgotten that. I always figured that's why FlowScan went out of business in the first place.

So I guess there's no market for a fairly priced monitor which uses inexpensive off-the-shelf sensors. Another business plan down the tubes!

Click to expand...

Nope- I think there's a huge market for that idea. While most modern diesels (say, post 2000 or so) have the fuel low data available internally, there are far more boats that have mechanical diesels that have a need for a good system that won't break the bank.

Pau Hana said:

...mechanical diesels that have a need for a good system that won't break the bank.

Click to expand...

Yup. When we went looking to replace our FloScan system that was damaged, I looked at systems that had good support and/or had been around for awhile. You still have to install it. We have a single engine so only 2 fuel sensors (supply and return) but you have to cut into the fuel system, plus power and data to the helm. As they say, “you only want to do it once”.

There’s not much out there. We looked at Maretron but with the 2 sensors plus the fuel flow monitor it was north of $1,000 on a deal. FloScan was south of that at the time and that’s who went with. It was still expensive but it’s a boat and no regrets.

Pau Hana said:

Nope- I think there's a huge market for that idea. While most modern diesels (say, post 2000 or so) have the fuel low data available internally, there are far more boats that have mechanical diesels that have a need for a good system that won't break the bank.

Click to expand...

Really? A huge market? Maybe huge for old boats, but that market itself is not that huge when it comes to comparing it to non-marine electronics. The marine industry in general is small, and you can find many companies that have had electronics of some type which have tried to make something for much cheaper than the status quo who are now out of business. I have at least 10 different devices that I can think of that fall into this category...

It's definitely a market, just not huge in the grand scheme of things. The other big thing that generally kills these smaller businesses is support.

The major reason they are so expensive for diesel engines is because they have to be extremely accurate. You are not just measuring flow in one direction, you are measuring it in two directions and subtracting that to get the number in which you are interested. For engines like Detroits, where the return is huge, the actual net flow is but a small percentage of of the total flow. So, if you have a reasonable 3% positive error going in and a reasonable 3% negative error in the return, the net error will be huge.

Plus, you have hot fuel coming out of the engine and you have to compensate for that as well. And you need to add pulsation dampeners.

I paid a lot for the floscans on my Detroits. I wouldn't do it again.