Electronic Barometer/Barograph What are important features?

[Onemoreproject]

I have thoroughly read several posts about electronic recording barometers. i have researched different units and found that they vary in price and features. They range in price from 50 to 250 for what i think i need.

I would like to know which of these features are most important:

The $200.00 NASA MateoMan stores 7 days of history, connects to the ships 12v system. But it does not have alarms or interfaces with a computer.

The 229. Weems and Plath runs on AA batteries, stores 48 hours of history, has alarms, but does not interface with a computer.

There are other contenders that have 24 hour history from Science Lab and Fisher. They run on batteries and have computer interface. They range around 150.00 to 190.00. so price isnt the issue. It depends on how much history is needed and if alarms are that important.

Looking forward to input!!

Thanks so much in advance!!

[jt11791]

A bit pricey, but I like the look of these: https://www.maretron.com/products/wso100.php

Apparent Wind speed
Apparent Wind direction
Barometric pressure
Air Temp
Relative humidity

Lots of good data pumped onto your N2K bus. Record and view however you like from there.

[Paul L]

In terms of practical use, I don't see needing g more than 24 or 48 hrs history. I also don't see yet another alarm as desired.
I like the Meteoman. It's a simple setup and has been reliable.

[Onemoreproject]

So, do you not feel like a computer intefa or alarms are necessary?

I Maretron looks like Maretron is nice equipment but i already have.

I am just looking for for live Barometric data.


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[a64pilot]

Accuracy was first and foremost in importance to me. To that end I wanted a lab quality instrument, hopefully calibrated to NIST standards.
I found this one, and you can buy it on Amazon.com. It comes with a multipoint calibration certificate with the test points annotated. A single point isn’t really a guarantee of accuracy.
https://www.thomassci.com/Instrument...le%20Barometer
It can be connected to and monitored by a computer, but I haven’t, and won’t.

[Paul L]

Where are you going to sail? When you get nearer the equator, like in a tradewind run, the pressure differences are very small between lows and highs.
If you are somewhere where you need to do weather forecasting via a barometer, then you will be watching it very regularly, so no I don't see any value to pressure alarms. We've been cruising for 7 years now (48*N to 37*S) and only lightly use the barometer. It can help when making longer passages to more temperate areas, such as Fiji to New Zealand. In this case you may be able to better predict a fronts timing or passage. But either way you are going to sail through it.

The electronic barometers allow you to calibrate them (use a close by airport reading), that is accurate enough.

GRIBs are your friend.

[Paul L]

Originally Posted by a64pilot

Accuracy was first and foremost in importance to me. To that end I wanted a lab quality instrument, hopefully calibrated to NIST standards.
I found this one, and you can buy it on Amazon.com. It comes with a multipoint calibration certificate with the test points annotated. A single point isn’t really a guarantee of accuracy.
https://www.thomassci.com/Instrument...le%20Barometer
It can be connected to and monitored by a computer, but I haven’t, and won’t.

That unit looks like a good deal.

[Onemoreproject]

Thanks so much for your reply. I really appreciate specific recommendations in my price range. I also saw a work station on the same web site, but don't know if the specs are what I need. Its less money and has some other features.

How does this one look?
https://www.thomassci.com/Instrument...with-Clock?q=*

[Onemoreproject]

I am in Nor Cal doing coastal sailing and headed south to Mex and then west to South Pacific and eventually NZ. So yes, I think an electronic barometer will be useful.

[a64pilot]

Originally Posted by Paul L

The electronic barometers allow you to calibrate them (use a close by airport reading), that is accurate enough.

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

[Onemoreproject]

Thanks for your reply. What do you mean by "multi point calibration over a significant range"?What type of Barometer do you have hanging on your wall?

[S/V Alchemy]

Originally Posted by Onemoreproject

So, do you not feel like a computer intefa or alarms are necessary?

I Maretron looks like Maretron is nice equipment but i already have.

I am just looking for for live Barometric data.


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No. I keep a paper log and could, if I chose, keep an Excel log on a tablet. I record the hourly reading there when on passage and can compare them to downloaded GRIBs, etc. I do not find the connectivity necessary as it's a single data input once an hour when I'm logging several others (sea state, wind, engine hours, RPMs, and so on). What is useful is seeing the trend and the speed of the rise or the drop of the pressure. That's just an eyeball estimate.

BTW, I have a venerable Speedtech digital baro I bought for $30 second-hand. Four AAAs keep it going for a year and it gives me six-hour trend lines and 24-hour history.

[S/V Alchemy]

Originally Posted by a64pilot

Accuracy was first and foremost in importance to me. To that end I wanted a lab quality instrument, hopefully calibrated to NIST standards.
I found this one, and you can buy it on Amazon.com. It comes with a multipoint calibration certificate with the test points annotated. A single point isn’t really a guarantee of accuracy.
https://www.thomassci.com/Instrument...le%20Barometer
It can be connected to and monitored by a computer, but I haven’t, and won’t.

That display is nearly identical to that of my Speedtech, which is no longer made. If it's the same kit, it's good and accurate once calibrated (I am currently on Lake Ontario at 74 metres above sea level).
Speedtech WeatherMate Barometer

[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!

[seandepagnier]

I use the bmp280. You can get modules for $4.

From there, openplotter and opencpn can read and display the data, including history graphs. You can set alarms for absolute values as well as rate of change.

I also build arduino boards which integrate this sensors, display wind speed/direction pressure and temperature on a small screen, and provide the nmea0183 data over the usb port.