Maretron TLM100 Ultrasonic Tank Sensor

The TLM100 is used to sense levels of liquid tanks using ultrasonic technology and transmit the liquid levels over an NMEA 2000 network. The TLM100 is NMEA 2000 certified so you can view any and all tank levels anywhere on the vessel using a compatible NMEA 2000 display such as the Maretron DSM250. The TLM100 is capable of sensing tanks up to 40" (1.02m) in depth. It can be used for diesel, fresh water, grey water, black water, and oil tanks. Unlike most tank senders that only work with rectangular tanks, the TLM100 can be calibrated for irregular tank shapes so you know the true level of your tanks.

The TLM100 can be mounted on tanks with a SAE J1810 5-hole mounting pattern, or to tanks using 1.5" NPT or 1.25" BSP threaded openings via available adapters (sold separately). The TLM100 has an optional airlock for black water applications to keep the face of the ultrasonic transmitter from fouling, and an optional focus tube to allow use on boats with planing hulls when the vessel spends a significant amount of time with the bow pitched up.

Product Features

  • NMEA 2000 Interface
  • Integrated ultrasonic level sensor
  • Replaces conventional tank sender
  • Maximum tank depth 40"
  • Works with diesel, fresh water, grey water, black water (holding tanks), and oil tanks
  • Not for use in gasoline tanks
  • Programmable tank capacity
  • Accommodates irregularly shaped tanks with 16 point calibration
  • 16 programmable tank types including fuel, fresh water, waste water, live well
  • Programmable tank number up to 16 per tank type
  • Bolts into existing fitting
  • SAE J1810 5-hole, 1.5" NPT, or 1.25" BSP Mounting
  • Most US boats use the standard SAE 5-bolt mount and do not need an adapter
  • Use optional black water airlock for holding tanks to prevent fouling (sold separately)
  • Use optional hull focus tube for planing powerboats (sold separately)
  • Uses an NMEA 2000 drop cable (not included) to connect to a T on the network backbone


To configure this unit for tank size and shape, you will need either (1) a Maretron DSM250 display or (2) the free Maretron N2K Analyzer software running on a laptop connected to the network through a Maretron USB100 interface.