Ferrite Meter

If the ferrite content of the steel steel is too low, then welding of stainless material may crack at elevated temperature or with high stress or vibration. Alternatively, if the ferrite content is too high, the weld may be weaker and corrode.

To address the need to measure the amount of ferrite in a sample the Welding Research Council introduced the Ferrite Number (FN) as standardized value which related to the ferrite content of an equivalently magnetic weld metal.

The volume percentage of ferrite can be estimated as about 70% of the FN but the relationship depends upon the type and origin of the stainless steel used and the measurement technique.

The Diverse Ferrite meter MF 300F + measures the Ferrite number (FN) of austenitic and duplex stainless steel weld material. It has a probe that is sensitive to ferrite content in a 10 mm area to a depth of approximately 1 mm. The instrument is calibrated using the secondary world standards held at "The Welding Institute". All 16 standards are used in the calibration giving an instrument with a measurement range from 0 to 115 FN. Transfer standards are supplied with the instrument allowing performance to be verified at any time.

Features of MF 300F + Ferrite Meter

• Non-destructive test of the ferrite content in a range of 0.1 to 115FN equivalent to 0.1 to 83% Fe in austenitic and duplex steel.
• Robust and portable
• Standard or peak measurement of Ferrite Number
• Estimate of ferrite percentage (70% of FN)
• Automatic zero on demand
• Supplied with 5 transfer standards allowing veracity of instrument to be checked
• Storage of 52 measurements, downloaded to PC with RS232/USB option
• Use with high temperature samples (air-cooled probe option)
• Simple measurement with small sample area.
• Units selectable between WRC-FN and ?.
• Calibration with standards traceable to TWI secondary standards
• Supplied in carry case