day wrote:Hehe hopefully I didn't miss something significantly easier and waste a bunch of time. The best phidget option I saw was http://www.phidgets.com/products.php?product_id=1137 but it is not for fuel and has an error of 5% listed, I suspect not accounting for repeatability or hysteresis.

I'm sure her insights will be useful. I don't think she was happy with readings and scraped it.

Actually I didn't do the project.
I never could make myself drill into the HUKY to mount the parts which are still in a drawer somewhere.

After almost two years I have found that roasting with nothing but the Artisan profile on the screen and a few tweaks of the gas and air has reduced the difficulty of roasting to only one thing: choosing the right bean.

And, Marko is correct, my parts were gathered with the intention of measuring air flow not gas pressure.

Well, here is the first test run. Note that these are garbage beans and I was testing out a variety of different aspects of the roaster at the time, so its not exactly a good roast, but demonstrate the meter readings well enough. Unfortunately my color coding is way off, it is the black unidentified line. It actually is laying on top of the pink line labeled mBar X as the extra device function has 2 slots, but the extech only outputs one.

So, Brian, where and how is this manometer connected to the gas line of the HUKY?

If I am understanding correctly, this mod makes it unnecessary to enter (via button or slider) the gas settings and yet still have them recorded with the profile. Yes?

Just connect it like a gauge, I haven't closed off the second port yet so barometric pressure could still affect readings but, I will have to get a cap from Home Depot and plug in a second tube to cap off. As long as you zero it out before each roast it is irrelevant I believe, beyond a few values if it changes during the roast. Also, this is the thick tubeing, and this beast is TIGHT I could not get it to budge at all either way now, had to remove it once and was forced to cut it off, very tight and secure connection.

Also, not sure what's happening but apparently if you close both the needle valve and the main flame adjustment off a vacuum builds up inside the pressure gauge tube such that after 24hoirs it will read -24mbar. I don't know how much negative pressure would build but it might be enough to damage the device, so I close the needle nose valve and then the main gas supply, leaving the flame adjuster open. Obviously it shouldn't be a problem, but I suppose it would be stupid to rely solely on the needle nose and leave the propane/ng open. Finally, the software updates too slowly to use it for settings, got to keep an eye on the actual meter.

I will look forward to seeing it when it is all working as planned )))

It is working fine, whatever is causing the negative pressure does not appear to be instrument error but rather something related to the design of the stove allowing air to exit once everything is closed but not enter?

As to regular usage capping one side is NOT the solution to barometric pressure. On reading more I found that a 3.3mbar change per hour is extremely fast and suggest an oncoming gale. A 1 mbar per hour change would suggest a rapid change in weather. Thus, a quick visual check and a zeroing out of necessary between roast would suffice, and in normal conditions would remain zeroed. All that to say it is pretty mich as it will be, eventually I'll put in a metal plate to stand it up against and prevent falling.

I would recommend that you add a good shut off like the one below and be sure to shut the propane off both at the tank and at the stove after each session.



I would worry about this connection:

I agree about the stove shut off and will probably do so, excellent suggestion. As to the tube, when first looking at them I felt the same, there are two types of tubes provided, a softer and harder. This is the harder tube and I assure you, it is REALLY on there. It was hard to get on, frankly. It has three solid barbs in it. I was trying to remove it at one point, easily applied a hundred plus pounds of force and it wouldn't budge in the slightest. Visually you can clearly see where the barbs have sealed themselves against the tube. Even after cutting the side it had to peel off the barbs. These tubes are very well designed for the purpose, and of course lpg has a very distinct smell, though certainly using caution and monitoring it over the years is advisable for any connection.

From the reading I have done, talking to some gas pros, and working with some of these tubes now, the fear some have is totally unnecessary and they work exactly as well as other connections.

Okay.
Just stay safe !!!!