Because a magnetic field is invisible, obtaining a complete, quantitative representation of it requires measurement of both its strength and its direction. The ability to do that might sound like science fiction, but thanks to a discovery made nearly 140 years ago, we have the gaussmeter—the tool we now use to determine the strength of magnets. 

The Hall Effect

Gaussmeters work because of the Hall Effect, a phenomenon discovered by Edwin Hall in 1879. In a nutshell, Hall found that a magnetic field will impact the flow of an electric current. We now know that we can measure this impact to determine the strength of a magnetic force. Using this discovery, the Hall Sensor was developed. Hall Sensors come in two different forms: transverse and axial. A transverse probe is ideal for measuring magnetic fields perpendicular to a flat surface, and an axial probe is ideal for measuring magnetic fields parallel to the probe handle.

Probe Types

Your probe houses the Hall Sensor necessary to get a reading. Without a probe, your gaussmeter is just high-tech plastic box. When you’re picking a probe, you get what you pay for. Cheaper probes tend to be flexible and easier to break. More expensive, rigid probes will hold up better under wear and tear.

Connection Cable

The connection cable links the gaussmeter to the probe. The length needed will depend on the work you’re doing. If you often need to extend yourself to get a reading, you’ll likely want a longer connection cable. Cables come in lengths from a few inches to multiple yards.

The Gaussmeter

Now for the exciting part: the gaussmeter itself. The features you’ll find on a gaussmeter will vary depending on the model, but there are a few you can expect to see:
  • Auto Zero: Resets the current reading even when a magnetic field is present.
  • Hold Function: Freezes the current value on the display.
  • Peak Hold: This feature shows only the highest reading the gaussmeter picks up during use.
  • Data Capture: Allows you to save past recorded values.
  • DC: For reading DC magnetic field currents.
  • DC Peak (Max): Records the maximum positive peak reading of a DC field.
  • AC RMS: Picks up the root mean square of an input.
  • Peak AC RMS (Max): Picks up the maximum positive peak value. 

Understanding the Reading

There are two units of measurement your gaussmeter may read: Gauss and Tesla. They measure the same thing, but they do it in different increments. One Tesla is equal to 10,000 Gauss. Some Gaussmeters will only read in one format or the other, although Tesla has become the most common in this industry. You should also note that different magnets will generate different readings, so ensure you have a gaussmeter designed with enough range to read your magnets. Tip: When working with magnets, you want a gaussmeter that can read up to 2 Tesla (20,000 Gauss).

Gaussmeters from Apex Magnets

Apex Magnets supplies reliable gaussmeters that ensure accurate results on each and every reading. Still aren’t sure what you need? Consult our customer service team for quick, detailed answers.