Yokogawa EML500-HV1 | Electromagnetic Speed Log Sensor 24V DC In Stock
Yokogawa EML500-HV1 | Electromagnetic Speed Log Sensor 24V DC In Stock - Image 2
Yokogawa EML500-HV1 | Electromagnetic Speed Log Sensor 24V DC In Stock - Image 3

Yokogawa EML500-HV1 | Electromagnetic Speed Log Sensor 24V DC In Stock

  • Model: EML500-HV1
  • Brand: Yokogawa Denshikiki (YDK)
  • Series: EML500 Series Electromagnetic Speed Log
  • Core Function: This is the core electromagnetic sensor probe that measures a vessel’s speed through water using Faraday’s law of electromagnetic induction.
  • Type: Marine Speed Sensor / Electromagnetic Log Probe
  • Key Specs: 24V DC operating voltage, approx. 6.9KG weight, compatible with LS571 probe assembly.
Category: SKU: ELECTROMAGNETIC LOG EML500-HV1

Description

Key Technical Specifications

  • Product Type: Electromagnetic Speed Log (EM Log) Sensor Probe
  • Operating Voltage: 24V DC
  • Unit Weight: Approximately 6.9 KG
  • Probe Model Compatibility: Designed for LS571 probe assembly
  • Cable Compatibility: Pairs with LS503 series cables (e.g., LS503*30M)
  • Measurement Principle: Electromagnetic induction (Faraday’s Law)
  • Manufacturer: Yokogawa Denshikiki Co., Ltd. (YDK)
  • Application: Marine vessel speed and distance measurement (Through-water speed)

Product Introduction

Finding spare parts for older marine navigation systems is always a headache, especially when the OEM marks them as “End of Life.” The Yokogawa EML500-HV1 is the electromagnetic sensor probe at the heart of the EML500 series speed logs. Unlike Doppler logs that rely on sound waves bouncing off particles, this unit uses electromagnetic induction to measure speed, which makes it incredibly reliable even in water full of air bubbles or sediment.The beauty of this sensor is its simplicity and ruggedness. Weighing in at around 6.9KG, it’s a solid piece of marine hardware designed to handle constant seawater exposure. It runs on a standard 24V DC supply, making integration into a ship’s existing power distribution straightforward. If you’re maintaining a vessel equipped with the older YDK speed log systems, getting your hands on a genuine, unused EML500-HV1 is often the only way to avoid a costly and complex system-wide upgrade.

 

Quality SOP & Tech Pitfalls (The Reality Check)

The Lab Report (SOP)
Because this is a marine sensor that gets mounted directly to the hull, our pre-shipment checks are strictly about physical integrity and electrical baselines:

  1. Visual & Physical Inspection: We thoroughly check the probe’s outer casing for any cracks, deep scratches, or signs of corrosion. The sealing surface must be flawless to prevent hull leaks.
  2. Coil Resistance Check: Using a high-precision multimeter, we measure the resistance of the internal electromagnetic coils to ensure they are within the OEM’s specified tolerance and haven’t suffered moisture ingress.
  3. Insulation Resistance Test: We perform a megohmmeter test to verify the insulation between the electrical terminals and the metal body, ensuring there are no ground faults.
  4. Cable & Connector Check: If supplied with cables (like the LS503), we inspect the connectors for bent pins and check the cable jacket for brittleness.
  5. Packaging: It is packed in a heavy-duty, waterproof-sealed crate with plenty of padding to protect the precision sensor face during shipping.

The Engineer’s Warning (Pitfalls)

  • Hull sealing is critical: The number one failure I’ve seen isn’t the electronics—it’s a bad hull seal. If the gasket isn’t seated perfectly during installation, you’ll get water ingress into the electronics housing, which will kill the sensor instantly.
  • Cable length matters: These electromagnetic sensors are highly sensitive to cable capacitance. If you are replacing the cable (e.g., using an LS503), make sure the length matches the system’s original calibration. Adding random lengths of marine cable will throw off your speed readings.
  • Don’t confuse it with Doppler: Make sure your display unit is actually an Electromagnetic Log (EML) and not a Doppler Sonar Log (like the JRC JLN series). The installation hull units and principles are completely different and not interchangeable.

 

Installation & Configuration Guide

Replacing a hull-mounted sensor requires dry-docking or a diver. Follow these steps carefully.

  1. Pre-Installation
    • ⚠️ Safety First: Ensure the vessel’s power to the Speed Log system is completely shut off at the breaker panel.
    • If replacing an old unit, take clear photos of the existing cable routing and terminal connections inside the ship.
  2. Removal
    • Disconnect the sensor cable from the internal junction box.
    • From the outside of the hull, unbolt and carefully remove the old probe assembly. Clean the hull seating surface thoroughly, removing all old gasket material and marine growth.
  3. Installation
    • Check the Gasket: Install a brand new, OEM-specified gasket onto the EML500-HV1 probe. Never reuse an old gasket.
    • Carefully feed the probe through the hull opening. Ensure the cable inside doesn’t get pinched or twisted.
    • Secure the probe from the inside using the specified mounting bolts. Tighten them evenly in a star pattern to ensure a uniform seal.
  4. Power-On & Testing
    • Reconnect the cable terminals inside the junction box, ensuring a watertight seal on the cable glands.
    • Turn the 24V DC power back ON.
    • Check the main Speed Log display unit. It should recognize the sensor. Take the vessel for a sea trial and compare the EML speed reading against GPS speed over ground (accounting for current) to verify accuracy.

 

Compatible Replacement Models

  • ✅ Drop-in Replacement: Yokogawa EML500-HV1. This is the exact OEM part. Given its EOL status, finding a new or new surplus unit is your best bet for a direct swap.
  • ⚠️ System Upgrade Required: Skipper Compact EML224. This is another electromagnetic speed log, but it is a completely different system. Replacing your YDK unit with this would require changing the hull unit, cabling, and the bridge display unit.
  • ❌ Not Compatible: Furuno DS-80 / JRC JLN-205 / JRC JLN-550. These are Doppler Sonar Speed Logs. They use acoustic signals rather than electromagnetic induction and cannot be used as a replacement for the EML500-HV1.

Frequently Asked Questions (FAQ)

Q: Is this the complete speed log system or just the sensor?
A: This is specifically the electromagnetic sensor probe (the part that goes through the hull). It does not include the bridge display unit or the amplifier/converter unit. You will need to pair it with your existing compatible YDK electronics.Q: My ship currently uses a Doppler log. Can I switch to this EML500-HV1?
A: Generally, no. Doppler logs and Electromagnetic logs use entirely different measurement principles and require different hull mounting arrangements and display processors. You should stick to the technology your current system was designed for.Q: Does this come with the 30M cable (LS503*30M)?
A: It depends on the specific lot. Sometimes it is sold as just the probe (LS571/EML500-HV1), and sometimes it is bundled with the cable. Please check the exact package contents listing or ask before purchasing to make sure you get the cable if you need it.Q: Why is this marked as “End of Life”? Should I still buy it?
A: Manufacturers eventually stop making older models to push newer versions. However, if your ship’s bridge is equipped with the EML500 processor, this is likely the only sensor that will work without replacing the entire system. For maintenance and repairs, an EOL genuine part is exactly what you need.Q: What voltage does this run on?
A: It operates on a 24V DC power supply, which is standard for most marine navigation and bridge equipment. Make sure your ship’s power distribution to the speed log amplifier is providing a stable 24V.

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