Definition - What does Banana Gauge mean?
This is a non-destructive testing gauge, which uses the principles of spring action and magnetism to measure the dry thickness of coatings in steel materials. It is the preferred method for use in a hazardous or inflammable atmosphere where electronic instruments cannot be used. It can also be used underwater for the same measurements.
Corrosionpedia explains Banana Gauge
This is a hand-operated instrument that may contain permanent calibration or digital calibration when used on surfaces; its light weight and compatibility makes it easy to use in different positions. It can be used on all types of surfaces because of the V" grooves in probe housing and the banana gauge base.
The gauge can be used to make standard measurements since it is recognized by international bodies like the International Organization for Standardization and American Society for Testing and Materials. Its accuracy is in mils to microns readings.
The efficiency of the instrument is not affected by mechanical shock or any other external forces due to the Carbide Probe (highly wear-resistant) and the rugged gauge housing. It is economical since no energy in the form of electricity is required. The automatically operated gauge will depend on the tension of the spring to create a pull-off force on the magnet, while the manually operated one depends on the operator through turning of the scale.