Nasa EML-2 Electromagnetic NMEA Speed Log

SKU: $002000087196 ISBN: 0735850166773

Product Code: NNEML-2

Price Includes VAT. 1 - 2 Working Days Standard Delivery £5.95 - UK Mainland.

£145.00 £174.16you save £29.16
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The EML-2 Nasa electromagnetic log measures the boat speed through the water with no moving parts. Robust and accurate, the sensor generates an alternative magnetic field below the boat and measures the resulting electric field which is produced by the boat as it moves through the water. 


The field is detected by small electrodes made of stainless steel on the underside of the sensor. Excellent linearity and a resolution of 0.1 Knot, over the range 0.2 to 40 Knots the interface box supplied with the system will amplify the signal and will convert it into speed trip and total distance reading and send it to any compatible NMEA-0183 display. The LED located on the interface box will flash each time NMEA data is sent out. 


The EML-2 system consists of a through-hull sensor, an interface box and optional clipper or target display units.


Technical Specifications


  • NMEA 0183 output sentences VLW + VHW

  • Supply voltage 12V

  • Supply Current 8mA

  • Speed Range 0.2 - 40 knots

  • Transducer cable length of 5.0 metres


EML-2 Electromagnetic Sensor Installation Instructions:


Before installing the sensor please make sure you always wear safety glasses and a dust mask to avoid injury. 


Once a suitable location is found when the boat is out of the water, drill a 3mm pilot hole from inside the hull. Using a 51mm (2.0 inch) hole saw, cut a hole perpendicular to ht hull from the outside the boat. 


Please note:

The sensor must be mounted in such a way so that it remains in non-turbulent water flow at all times. This must be positioned as close as possible to the centre line where the water flow is unrestricted and can be easily accessible for cleaning. 


Is vital to avoid areas around devices which could create electrical or magnetic interference. 


Make a small chamfer around the hole. Just enough to fit the 2mm skin fitting flange. Sand and clean the hole in and outside so that the sealant will properly bond to the hull.


Using a well proper marine silicone sealant (CT-1 Sealants will be perfect for this bonding job) apply about 2mm of sealant around the skin fitting flange where it contacts the hull and also up the sidewall to a distance of 3mm higher than the combined thickness of the hull and to hold the nut securely in place. 


From outside the hull gently push the house into the mounting hole slowly with a twisting movement so that the excess of sealant is being pushed out. 


From inside the hull apply a 2mm thick layer of sealant around the hole which is equal to the diameter of the rubber washer. Place the rubber washer over the skin fitting and bend down onto the sealant. Apply more sealant to the upper face of the rubber washer so that you create an even coat and tighten down the nut - make sure you do not overtighten it.


When this is done please remove all surplus sealant from the inside and outside of the hull and leave until the sealant has cured. It is recommended that the area around the skin fitting is cleaned and the whole assembly is fibre glassed into the hull. Ensure that 20mm of the top thread remains free of resin or sealant.


For information about installing the interface box and the display unit refer to the installation manual available for download on the downloads tab on this page.


Delivery & Returns

We ship chandlery, clothing and marine equipment around the world and always endeavour to get your products to you as quickly and as cost-effectively as possible. We will dispatch your order as soon as possible, usually the day it is received for orders placed before 2PM. Our stock is controlled such that all items bought online are available in stock with our shop or supplier. If there is any delay due to a product being out of stock, or there is a longer lead time, for example, in the case of ‘Special Order’ items, or having a longer lead time for production, we will contact you, however, this will also be suggested at the checkout. In such cases, we will advise when the product will be delivered (or is available for collection if you have opted to collect from our store).

FREE Standard UK Mainland Shipping 1 -2 Working Days - Orders Over £150 - (Excluding Weekends & Bank Hollidays)

Standard UK Mainland 1 - 2 Working Days (Excluding Weekends & Bank Hollidays) - £5.95

Next Day Delivery (Please note that orders must be received by 1400hrs for next day delivery. In some instances, we may be able to dispatch later in the day for next day delivery but this cannot be guaranteed. - £6.95

Scotish Highlands & Islands 2 - 3 Working Days (Excluding Weekends & Bank Hollidays) - 14.45

Isle of Wight 2 - 3 Working Days (Excluding Weekends & Bank Holidays) - £9.45

Northern Ireland 2 - 3 Working Days (Excluding Weekends & Bank Holidays) - £14.95

Our policy is simple – you have up to 30 days to return your purchase if it’s not suitable or you’ve changed your mind. We want you to be completely happy with your purchase from Fox’s Chandlery, but if for any reason you need to return an item/s to us, you must notify us in writing within 14 days of delivery that you intend to return the item/s and return the item/s to us within 30 days of delivery and we’ll be happy to exchange for another item or make a refund by the same method used to pay for the order.

Return goods purchased in-store

Simply bring your order confirmation or delivery note and the item you wish to return or exchange, unused and in its original packaging, to our till point in the shop. If you paid by debit or credit card, please ensure you also bring the payment card you originally used to buy the item/s.

Return goods via Royal Mail or Courier

1. Download and print our returns form here.

2. Complete your reason(s) for return on the Returns Form included with your order.

3. Enclose the Returns Form with the product and package up securely.

4. Please use the original packaging if at all possible, but remove original postage labels.

5. Use the Returns label from the delivery note and always obtain proof of postage.

6. If you need your item/s to be collected because it's large or heavy please call our online team on +44 (0) 1473 694725.

If you need to add or remove items from your order, change the details of your delivery address or cancel the order completely, please contact our Online Team for advice on +44 (0) 1473 694725 between 0900 and 1730 Monday to Friday or email us. Please quote your order number and order date. If your order has already been dispatched or delivered, then you will need to follow our Returns procedure in the event of any unwanted products.