Any disadvantages to ultrasonic wind sensor?

[Saltyhog]

Based on what other have done here, I'm planning on installing a Maretron WSO100 on my masthead. This will be my only wind sensor. It will feed the N2K bus and the data to be used by yet to be purchased displays and autopilot (likely SIMRAD). What if any are the disadvantages to this vs. a traditional mechanical wind direction / speed mast head unit? The only 2 that I can think of are that it's possibly heavier and possibly uses more power. The power thing I'm not too sure of as the SIMRAD masthead sensor (the 508) that is also N2K (aka SIMNET), is pretty sparse on specifications, including power. One of the goals of the system is to have the autopilot steer to the wind. Will the WSO100 do a better job for this?
-Tom

[s/v Jedi]

Originally Posted by Saltyhog

Based on what other have done here, I'm planning on installing a Maretron WSO100 on my masthead. This will be my only wind sensor. It will feed the N2K bus and the data to be used by yet to be purchased displays and autopilot (likely SIMRAD). What if any are the disadvantages to this vs. a traditional mechanical wind direction / speed mast head unit? The only 2 that I can think of are that it's possibly heavier and possibly uses more power. The power thing I'm not too sure of as the SIMRAD masthead sensor (the 508) that is also N2K (aka SIMNET), is pretty sparse on specifications, including power. One of the goals of the system is to have the autopilot steer to the wind. Will the WSO100 do a better job for this?
-Tom

The disadvantage is that you get to spend less time up the mast replacing the sensor after birds attacked it again, missing the lovely views you get from up there

It is not perfect every time because my first one quickly filled up with water and I found somebody else with the same problem on the net. But others that I know never had that and my replacement is good too.

[Saltyhog]

Originally Posted by s/v Jedi

The disadvantage is that you get to spend less time up the mast replacing the sensor after birds attacked it again, missing the lovely views you get from up there

It is not perfect every time because my first one quickly filled up with water and I found somebody else with the same problem on the net. But others that I know never had that and my replacement is good too.

You mean I won't get to use my trusty climbing harness on a regular basis I will miss that. I guess my concern is that most of the installs of the ultrasonics that I've noted on CF are on larger boats. I haven't seen the unit to get a sense of how it'll fit. Nick -In your opinion, how does the WSO100 compare to an older sensor weight/windage wise? This is going on a 38 foot boat. For comparison the LCJ Capteurs sensor is *really* small and light and low power. I'm just not willing to wait to find out how they work in the wild. Too new and the company is too far away. -Tom

[s/v Jedi]

The only issue is on how to mount it. If there is not enough room on top of the masthead, then you need to use a L-bracket with 1" threads. You can buy these as part of a rail-mount.

The windage of the Airmar is less than an old-style sensor that needs to wind to propel it. It's also stream-lined.

[Saltyhog]

Nick - Thanks! I really appreciate you input. You seem to have thought a lot of this through and have considered the issues. I'm installing a Lopolight Tri-anchor. I saw a picture of someones install that put the sensor over that with a tri-pod arrangement where the legs aligned with the color transitions of the light. Do you think that would be better than a bent tube mount to move the sensor forward of the mast? I guess I'm not sure what the up flow off the jib will do the the sensor. I think the bent tube would be easier to make. I think I could have that bent and welded from some aluminum pipe.

[s/v Jedi]

The bent tube sounds better. Make them cut the threads directly into it, plus make sure the have enough length straight up just below the sensor because both the connector and an in-line terminator must fit in there. Will easily be 4" if not more. You need to get those parts before deciding so that you can verify it will fit.

[DotDun]

A disadvantage of ultrasonic? --- You will cry for a longer time when you crunch it on the bottom of a bridge! It costs more to replace than cups and feathers.

[Dockhead]

For whatever it's worth -- maybe little so far since I haven't tried it yet -- I mounted my WSO100 on a straight 60cm stainless pipe screwed into a Shakespeare 15cm antenna mount socket. That, in turn, I bolted to the front part of the masthead truck, starboard side.

So it sticks up 75cm above the masthead truck -- I hope out of the backwash of the jib.

The old wind transducer continues to live on the masthead truck, too -- on the port side. Nothing like having backup -- comparison.

A bent pipe would help to get the WSO100 out of the backwash, but I was worried about the lever arm -- shaking loose up there -- so decided to leave it straight, at least for now. If in comparison with my old wind instrument I can see that there is some disturbance from backwash, then I might try something else, although it will not be all that fun doing that work 75 feet up in the air


It seems no one answered your question about power consumption. This is a real easy question with respect to any piece of N2K gear. All N2K have an LEN rating -- Load Equivalency Number. For the WSO100, it's 3. Each LEN amounts to 150 milliamps, so that's 450 milliamps. At 13.6 volts, that's 6.8 watts.

[DotDun]

Originally Posted by Dockhead

It seems no one answered your question about power consumption. This is a real easy question with respect to any piece of N2K gear. All N2K have an LEN rating -- Load Equivalency Number. For the WSO100, it's 3. Each LEN amounts to 150 milliamps, so that's 450 milliamps. At 13.6 volts, that's 6.8 watts.

errrr...... a LEN is 50ma, not 150ma. So the WSO100 draws between 101-150ma.

[Saltyhog]

Originally Posted by Dockhead

For whatever it's worth -- maybe little so far since I haven't tried it yet -- I mounted my WSO100 on a straight 60cm stainless pipe screwed into a Shakespeare 15cm antenna mount socket. That, in turn, I bolted to the front part of the masthead truck, starboard side.

So it sticks up 75cm above the masthead truck -- I hope out of the backwash of the jib.

The old wind transducer continues to live on the masthead truck, too -- on the port side. Nothing like having backup -- comparison.

A bent pipe would help to get the WSO100 out of the backwash, but I was worried about the lever arm -- shaking loose up there -- so decided to leave it straight, at least for now. If in comparison with my old wind instrument I can see that there is some disturbance from backwash, then I might try something else, although it will not be all that fun doing that work 75 feet up in the air


It seems no one answered your question about power consumption. This is a real easy question with respect to any piece of N2K gear. All N2K have an LEN rating -- Load Equivalency Number. For the WSO100, it's 3. Each LEN amounts to 150 milliamps, so that's 450 milliamps. At 13.6 volts, that's 6.8 watts.

Hmmmm.... From the WSO100 data sheet:

Operating Voltage 9 to 16 Volts DC Voltage
Power Consumption <150mA Average Current Drain
Load Equivalence Number (LEN) 3 NMEA 2000® Spec. (1LEN = 50 mA)

I'm pretty sure 1 LEN = 50ma (per other sources) and that would agree with Maretron's numbers. If it were drawing 450mA, I wouldn't even consider it. 150mA (about 2W) is right on the line for me. I'm pretty stingy with power. You take 2 hits on power with this. 1) It consumes more power in general and 2) you're likely to leave it on all the time due to the weather sensors.


It'll be interesting to see how the new sensor compares with the old. Is your old sensor also N2K?

[Dockhead]

Originally Posted by DotDun

errrr...... a LEN is 50ma, not 150ma. So the WSO100 draws between 101-150ma.

Correct, correct, correct! Sorry, brain flatulence . . . My bad . . . .

[Dockhead]

Originally Posted by Saltyhog

It'll be interesting to see how the new sensor compares with the old. Is your old sensor also N2K?

No, it's a classic Raymarine ST60 transducer. These are very good; a kind of benchmark in their day. I have had very good luck with them (when seagulls weren't snapping them off ) and it will be interesting to see how the new WSO100 stacks up in comparison.

[s/v Jedi]

Originally Posted by DotDun

A disadvantage of ultrasonic? --- You will cry for a longer time when you crunch it on the bottom of a bridge! It costs more to replace than cups and feathers.

Not me.. my broken B&G sensor was $1,275 and the Maretron was just $600... less than half the price!

[Saltyhog]

My existing wind sensor is the original 1987 Data-Marine. Still works, kind of. I actually really like the old round displays. They interface to nothing else though. I (briefly) toyed with the idea of engineering new guts for the display heads. It would be a cool project in a way. An embedded processor with a CAN interface. How difficult could it be? (I do this sort of thing IRL) Then I came to my senses. I don't need *any* more projects.

[DotDun]

Originally Posted by s/v Jedi

Not me.. my broken B&G sensor was $1,275 and the Maretron was just $600... less than half the price!

I think the RM transducer can be had for ~$300.

My problem is a 65' mast living amongst a lot of 65' bridges. It's 'at the top of mind', so to speak! I've threatened to take a hack saw to the top 18", or relocate. I prefer the later, but......