Electronic Barometer/Barograph What are important features?

[indimini]

If you have a NMEA 2000 network and want barometer on your chart plotter, it's hard to bead the yachtd unit for $99. It requires no setup, simply plug it into your network.

[boom23]

The Mintaka Duo+ looks like a great product.

Mintaka Digital Barometers | Handheld Barographs

[NewMoon]

Originally Posted by S/V Alchemy

Speedtech WeatherMate Barometer

That's the one we have. Still spot on, once calibrated at the start of each summer cruise, after 20 years. Shows pressures through the past 1, 3, 6, 12, and 24 hours, so we can easily see the rate of change. Seems to be all we need.

[mikecambrai]

As far as barometric pressure is concerned I always want to know the actual pressure within a couple of millibars (so that I can compare with a local forecast), and a graph.
It is the rate of change in pressure which is most likely to help me. When fronts pass by you can easily see them from a barograph and comparing the pressure change with wind direction is even more helpful.
I use an electronic gadget which is used by hikers in the mountains. The prices are usually lower as it does not say 'marine' on it!

[Exile]

Originally Posted by GregW1309

I’ve been using a free app “Barograph:Barometer&Altimeter” which uses the built in iPhone barometer. Sends me notices when the pressure is rising and falling. Also plots the pressure, I have a month of data so far. Seems to work fine on an iPhone 8 Plus. Very basic but free!

Good to hear some positive reports on these iPhone apps, especially since reliable data showing multi-day trends is generally the most important feature for sailors. Might be worth noting that they require the phone itself to have a built-in barometer, a feature which started with the 6s & 6-Plus but not the SE (which is a smaller 6). Not sure about the Android phones.

One question is whether the iPhone apps (or the one you have) require internet service to work? I would think not, since the data is presumably relying on the built-in barometer and not a GPS fix mated to a position on a weather chart.

Thanks for the input.

[Onemoreproject]

Originally Posted by GregW1309

I’ve been using a free app “Barograph:Barometer&Altimeter” which uses the built in iPhone barometer. Sends me notices when the pressure is rising and falling. Also plots the pressure, I have a month of data so far. Seems to work fine on an iPhone 8 Plus. Very basic but free!

Does that app work offshore?

[conachair]

Originally Posted by NewMoon

That's the one we have. Still spot on, once calibrated at the start of each summer cruise, after 20 years. Shows pressures through the past 1, 3, 6, 12, and 24 hours, so we can easily see the rate of change. Seems to be all we need.

Same here, been onboard for years. Never bother with calibration, it's never far out from a nearby airport and it's rate of increase/decrease that's of real interest.
As mentioned above, a Bmp180 /280 is very accurate, a barograph in Opencpn dashboard with a sensor costing less than a beer could well be as accurate as standalone units costing hundreds of dollars.

[Onemoreproject]

Originally Posted by Exile

Good to hear some positive reports on these iPhone apps, especially since reliable data showing multi-day trends is generally the most important feature for sailors. Might be worth noting that they require the phone itself to have a built-in barometer, a feature which started with the 6s & 6-Plus but not the SE (which is a smaller 6). Not sure about the Android phones.

One question is whether the iPhone apps (or the one you have) require internet service to work? I would think not, since the data is presumably relying on the built-in barometer and not a GPS fix mated to a position on a weather chart.

Thanks for the input.

Thanks for that. i just installed it on my iphone 6. I put my phone in airplane mode so as to cut off wifi and 4G internet and its still recording data. There is a lot of varitation. it started at 96.774 and has risen to 96.733 in 4 minutes. I am not sure i would be able to look back over a 24 hours worth of history. But i like having it on my phone!I think what is most practical is a stand alone monitor that is always on easily visible for all to see.

[Exile]

Originally Posted by Onemoreproject

Thanks for that. i just installed it on my iphone 6. I put my phone in airplane mode so as to cut off wifi and 4G internet and its still recording data. There is a lot of varitation. it started at 96.774 and has risen to 96.733 in 4 minutes. I am not sure i would be able to look back over a 24 hours worth of history. But i like having it on my phone!I think what is most practical is a stand alone monitor that is always on easily visible for all to see.

If these apps prove to be reasonably accurate I was hoping to use my phone as the stand-alone monitor you describe. I usually have it parked in a mount & plugged in at the nav table for other purposes anyway. Does it allow you to do an initial calibration?

[Paul L]

Originally Posted by a64pilot

No, a single point like that only means that at that one point it’s correct. What is more important is to ensure that as the pressure rises and falls, it still reports correctly. For that you have to have a multi point calibration over a significant range. The one I have hanging on our wall I adjusted to read correct when the pressure was 30.02 or so, but it barely moves. It didn’t go below 29.95 or so when Irma went past.
It’s a wall decoration, nothing more. But it’s accurate whenever the pressure is 30.02

Do you really think that you will actively be making different passage decisions based on an NIST calibrated barometer vs my single point calibrated Meteoman unit? In this case close is good enough and relative changes are more interesting than absolute.

[El Pinguino]

I have one of these https://www.zapals.com/sunroad-fr500...SABEgL9XvD_BwE velcroed to the chartroom bulkhead. Cheap and cheerful.

If really keen you could buy one of these Grove - Barometer Sensor (BMP280) - Seeed Wiki

I don't think absolute accuracy is essential... what does matter is the trend ... quite a few summers back I was trading around Bay of Bengal/South China Sea and it was a company requirement to log the barometric pressure every two hours....

[Onemoreproject]

Thats what this forum is all about. Examining theoretical situations with real life experience.
Thanks!

What do you think about this stand alone device vs one incorporated in a chart plotter? I found this one for 125.00 which is 75.00 less than the MateoMan. Difference between this and MateoMan is in the display and it only stores 24 hours of history.

https://www.thomassci.com/Instrument...le%20Barometer

[Paul L]

Originally Posted by Onemoreproject

Thats what this forum is all about. Examining theoretical situations with real life experience.
Thanks!

What do you think about this stand alone device vs one incorporated in a chart plotter? I found this one for 125.00 which is 75.00 less than the MateoMan. Difference between this and MateoMan is in the display and it only stores 24 hours of history.

https://www.thomassci.com/Instrument...le%20Barometer

I would much prefer a stand alone device, as you'll want to check it while at anchor when the chart plotter is off.

[conachair]

Or make one...

https://sdfjkl.org/blog/2017-08-09-nanobaro/

Though there are little wifi boards drawing next t o no power like the esp32 which could do the job of the arduino in the example above, create a web page to display the last day/week of readings and send NEA sentences out over wifi/serial to openpn for viewing on a dashboard & automatically inserting into the konni logbook.

[Onemoreproject]

Hadn't thought about that, but definitely agree. Just another good reason to have it visible all the time.
So you like your MateoMan, do you think it has any advantages over the one i posted a link to??