Devices with marine approval certification to use on ships for measuring liquid level and converting it to an electrical signal to send to other instrumentation.
- DMK 458 Seawater Low Range Pressure Transmitter - Sea water corrosion resistant low range pressure transmitter for marine, ship and offshore engineering.
- LMK458 Marine Approved Hydrostatic Level Transmitter - Marine approved level transmitter with 4-20mA output for measuring level of contents inside ship ballast, fuel, liquid cargo or wastewater tanks
- LMK 487 Submersible Ballast Tank and Draught Level Pressure Transmitter - A 22mm diameter titanium body seawater depth and level probe with a 4-20mA output with Lloyds and DNV-GL ship approval, for monitoring the quantity of ballast or the draft of a ship’s hull.
All voyage and safety critical equipment on a ship must be certified by the same marine approval body that audited and registered the whole ship.
A marine approved device is one that has been tested and certified by a recognised body such as LR (Lloyd’s Register), GL (Germanischer Lloyd), DNV (Det Norske Veritas), ABS (American Bureau of Shipping) and CCS (China Classification Society) for use on a ship.
The marine approval process involves an initial and continuous periodic product assessment to inspect random production samples, ensure adequate production and inspection processes, procedures, documentation and quality control, and review the current product design and any future design iterations for compliance with the type approval.
A liquid level sensor is an instrument for measuring the height of a liquid and converting it to an electrical signal which is sent to other instrumentation to display, monitor, log or control the liquid level.
There are many different types of technology use to measure liquid level, there are sensors that can be mounted above the liquid such as ultrasonic or radar which bounce a sound or electromagnetic wave off the surface of the liquid and use the travel time to determine the distance from the liquid surface.
For liquid filled tanks there are sensors which can be attached externally, such as floats running up and down a liquid filled tube connected at the bottom of the tank, or a pressure sensor installed in a hole in the bottom of the tank which measures the pressure generated by gravity acting on the liquid.
Another method is to lower a probe into the tank and immerse it in the liquid such as a capacitive probe which detects the changing capacitance charge as the length of the probe is exposed to varying proportions of liquid and air, or pressure sensors which measure the pressure generated by gravity acting on the surrounding liquid.