NASA marine EML-2: is there anybody using it?

[iv3wjr]

Hi to all,
searching for *non* paddlewheel speed transducers I found this em-log sensor:
https://www.nasamarine.com/product/electromagnetic-log/


On the Internet I did not find any review or test of it.

I know there is a better technology for speed sensing (ultrasonic) but ultrasonic sensors like Airmar UDST800 are *way* more expensive. I wonder if any of you is using the EML-2 and to read his impressions and comments.


The network I have on Orion is Raymarine SeatalkNG (i50 for speed) so I understand I should translate NMEA0183 VLW and VHW sentences to NMEA2k but I do not know to which PGN.



Fair wind

[jbchrist]

Hi
Two years has passed since you put out this note. But I can tell you that I have been using the EML2 during season 2021 with satisfactory (=no problems) results. My boat is a trimaran doing speeds up to 25 knots (aarhm.. more like 18 with me at the tiller), so a linear response is important.
Jorgen

[iv3wjr]

Great Jorgen, thank you for sharing your experience. Can you please tell how did you interface the EML-2 to your network? Is it NMEA2000 like? Was it straightforward?


18 knots for me is warp speed, I live in the 3-8 range with my boat.


Roberto

[jbchrist]

On my boat, the EML-2 is connected via NMEA0183 to a B&GZeus. From here the data is distributed to all other devises. So if you have NMEA0183 you are OK.

The only downside to the EML-2 I can think of is its design. As all other NASA-Marine, visuals is not its strong side. And it is completely open for intrusion of moisture. So put it high and dry. Support at NASA is very friendly and speedy. An important factor.

The devise has a competitor in Airmar DST Ultrasonic. The technology is different (ultrasonic versus electromagnetic) and I cannot really say which would be a winner in the long run. The Airmar certainly has more advanced calibration capabilities but the price is also some 8 times the NASA-devise. So for the same price you could drill 8 50mm holes in your boat and create a very advanced speed data acquisition system (... just joking).

The EML-2 is certainly worth a try - especially if you have problems with the spinning wheel other sensors getting stuck.

Jorgen