Level transmitter symbol
Also called LT
A level transmitter measures the liquid level in a vessel or tank and sends it to the control system.
What the level transmitter symbol means
A level transmitter measures the liquid level in a vessel or tank and sends it to the control system.
How it is drawn
A field instrument circle tagged LT, connected to the vessel by two lines for the upper and lower connections.
The level transmitter symbol in each standard
Drawn as ISA 5.1 defines it, as on most US and international legends.
ISO 10628-2 does not cover instruments. On ISO-based P&IDs they are drawn as IEC 62424 PCE requests, or to ISA 5.1 on many international projects.
German (DIN): Füllstandmessumformer. See DIN P&ID symbols.
Where you see it on a P&ID
On vessels, separators, tanks and columns.
Tag codes
The level transmitter is commonly tagged:
- LT
- LIT
Tag formats follow the project numbering procedure. For instruments, the letters follow ISA 5.1, explained on the instrument symbols page.
Related symbols
Frequently asked questions
What does the level transmitter symbol look like on a P&ID?
A field instrument circle tagged LT, connected to the vessel by two lines for the upper and lower connections.
What is a level transmitter used for?
A level transmitter measures the liquid level in a vessel or tank and sends it to the control system. You will find it on vessels, separators, tanks and columns.
What tag does a level transmitter have?
It is commonly tagged LT, LIT. The exact tag format comes from the project numbering procedure and the legend sheets.
Is the level transmitter symbol the same in ISA and ISO?
ISO 10628-2 does not cover instruments. On ISO-based P&IDs they are drawn as IEC 62424 PCE requests, or to ISA 5.1 on many international projects. Companies vary the details, so always check the legend sheets at the front of the P&ID set.
What is the level transmitter called in German?
Füllstandmessumformer. On a German R&I-Fließschema it is drawn to DIN EN ISO 10628-2 and DIN EN 62424.
- In production since 2014
- Thousands of daily users
- On MODEC FPSO projects since 2016