Data Sheet

TRM-UST is a combination fuel and water sensor that responds to fuel leaking into the interstitial space of a double wall tank or to ground water leaking into the containment space from the outside.

TRM-UST is small in both diameter and rigid length. This design feature allows the sensor to be inserted into the limited space between inner and outer tanks shells. The space available to change direction between the bottom of the riser pipe and top of the inner tank is very tight and that requires a small probe

TRM-UST is available in one size: 2 ½” long x ½” diameter. The outer surface is protected by polyolefin shrink tube.

TRM-UST is supplied with 10m (32 ft) of tray rated, outdoor, two wire leader cable (longer lengths can be supplied on request).

The recommended monitoring option for TRM-UST is TRM -Easy5-Relay-U or TRM-Easy5-Panerl.  The Relay or Panel provide a separate “fuel leak” and “water leak” output contact .

CSA Group has examined TRM-UST and considers the sensor to be “Simple Apparatus” per CSA /EN/IEC/UL 60079-11 Clauses 5.7 a and b. As such TRM-UST may be installed in hazardous areas when connected to the monitoring device via an approved zener safety barrier. The safety approvals granted to the zener safety barrier apply to the installation as a whole.

Key Features

Form Factor:

  • Small diameter, short length cylindrical probe

Dimensions:

  • ½ ” diameter x 2 ½” rigid length

Leader/Jumper cable:

  • Supplied with factory standard 10m (32 feet) of three wire leader cable. (longer leader cable can be quoted on request)  Leader cable can be spliced to extended length jumper cable in the field. The maximum recommended jumper cable per TRM-UST probe is 2500 feet as limited by zener safety barrier inductance and capacitance parameters)

Integrity Monitoring:

  • Loss of cable continuity is signaled as an ALARM condition as is detection of either fuel or water.

Response time:

  • Gasoline, Diesel, Jet Fuel < 3 seconds
  • Water < 3 second

Resettable:

  • Sensor can be reset in the field using naphtha as a diluting solvent and air drying

Reset time:

  • varies by fluid type, ambient temperature and air flow.  Water and gasoline will reset almost immediately. Diesel and jet fuel cleaning and reset time varies depending on temperature.  Naphtha rinses and air drying are usually required for diesel or jet fuel reset.

Simple Apparatus Statement:

  • CSA Group has examined TRM-UST and considers the sensor to be “Simple Apparatus” per CSA /EN/IEC/UL 60079-11 Clauses 5.7 a and b. As such TRM-UST may be installed in hazardous areas when connected to the monitoring device via an approved zener safety barrier without adversely impacting the safety approvals associated with the zener barrier. The safety approvals granted to the zener barrier apply to the installation as a whole. TRM Sensors recommends MTL 7789+ zener barrier. One barrier and one TRM Relay Unit Type-CV is required per TRM-UST probe.

Recommended monitoring options:

  • TRM-Easy5-Relay-U  or TRM-Easy5-Panel