What does the ISA 5.1 first letter M stand for?

In ISA 5.1, the first letter M stands for User's choice, commonly Moisture. It can also stand for Mass, rare.

What second letters commonly follow M in ISA 5.1 tags?

Common combinations include MT (Transmitter, MT. Moisture transmitter), MI (Indicator, MI).

M - User's choice, commonly Moisture

Q: What are example ISA 5.1 tags starting with M?

MT-401 (Moisture transmitter, common on natural gas dewpoint and dryer outlet streams).

Reference for the ISA 5.1 first letter M. Moisture is the working assignment for M on most plants. Dewpoint downstream of TEG units, water content in gas processing, chip moisture in pulp mills, raw mill moisture in cement. The tag itself doesn't tell you which one. The service description column does. Calibration intervals vary wildly between dewpoint sensors and bulk moisture analyzers, so don't assume one calibration plan covers your whole M scope.

Start a workspaceExtract ISA 5.1-compliant I/O lists

Read one of your own drawings.

Drop a P&ID, instrument index, or schedule. Tagsight reads it to the tag and opens a workspace you keep when you sign in.

PDF · DWG · DXF · TIFF · PNG · XLSX

Browse filesor drop a file anywhere on this card

Also stands for.

Mass, rare

Common second letters.

Transmitter, MT. Moisture transmitter

Indicator, MI

Example tags.

MT-401

Moisture transmitter, common on natural gas dewpoint and dryer outlet streams

Typical placement.

On gas-treatment streams, TEG dehydration, molecular sieve dryers and on solid-handling streams, cement raw mill, pulp mill chip moisture.

Related

GlossaryISA 5.1 IndustryLNG IndustryCement IndustryPulp and Paper ISAISA letter A - Analysis ISAISA letter H - Hand