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DSP-521N Gaussmeter: Ignores Powerlines

Lowcost Gaussmeter can Ignore Powerlines!


DSP-521N AC Gaussmeter

The DSP-523's little brother, the DSP-521N takes the "do one thing and do it well" philosophy to new level.

Ignore Powerline Fields

The DSP-521N shows you the total field strength, and the field strength with powerline fields ignored.  This is done by using fast and accurate DSP filtering techniques to notch out 50/60 Hz and all harmonics of 50/60 Hz.  Compare the two readings on the same screen to instantly know if the fields you're measuring are from powerlines or other sources.

Fully Automatic

Just turn it on and go, the DSP-521N will automatically detect if you're where 50Hz  is used or 60Hz is used.  Travel all over the world with your meter, with no worries about changing settings.  No menus, no complications, no errors - just an ON/OFF switch - as it should be.

Highest Resolution EVER

NEW Jan 8, 2010 -> The DSP-521N resolution is now 0.01 mG over the entire 0 to 99.99 mG range!  This is the only AC gaussmeter in the world to feature resolution to 0.01 mG over such a wide range!

Fastest Update Rate EVER

The DSP-521N features a super fast update rate of 4 times per second.  This fast update rate allows you to sweep areas faster, as well as track down sources faster.

Backlit LCD

A green LED backlight lets this meter go where others can't - the dark.  Want to conserve battery life or don't want the backlight?  No problem, turn it off with a simple jumper in the battery compartment.

Accurate Readings in a Small Package

True-RMS readings are accurate for not only pure sine waves, but any field, even transient fields.  Think you can only get True-RMS from big bulky desktop meters?  Think again, the DSP-521N weighs just 3.8oz and can easily fit in your pocket, and is smaller than most other handheld gaussmeters.  At just 4.4" x 2.6" x 1.1", it makes a great, but slim, addition to any toolbox.

Finally, a meter that tells me what I'm measuring!

Most magnetic fields around us are at powerline frequencies - 50Hz in Europe, and 60Hz in North America.  These fields also contain strong harmonics at multiples of the main frequency (60, 120, 180, 240 Hz, etc).  By placing sharp and accurate notches at every frequency associated with powerlines, you now have the capability of measuring everything else.  In other words, a field at 20, 40, 70, or 100 Hz will be measured, while 60, 120, 180 Hz, etc., will be ignored.

 By comparing the total field strength with the field strength with powerlines ignored, you can know instantly whether a field is from powerline frequencies or another source.  Measure the field from a DC motor, or the fields inside your car without worries of contamination from powerlines.  A great tool for looking for transient fields not associated with powerlines!



  • Accuracy: ±(4% + 2 digits) from 48 to 62 Hertz
  • Flat frequency response:
    • ±½dB 30 to 500 Hz
    • -3dB 15 to 550 Hz
  • Range 0-99.99 mG
  • Resolution: 0.01 mG over entire range
  • Single Axis Detector
  • True RMS Measurements
  • Fast Update Rate: 4 times per second
  • Green LED Backlight
  • Runs on one 9V Alkaline battery (included), lasts ~15 hours
  • Unit Weight (without battery): 3.8 oz
  • Unit Dimensions: 4.4" x 2.6" x 1.1"
  • 1 Year Warranty
  • Made in the USA


Product Reviews

 "A very useful device and reasonably priced!"  - Susan G.

   This gaussmeter is great, so simple a child could use it.  I was able to reassure myself that a house I was looking to buy was not getting too much EMF from a nearby electrical substation.  On the other hand I was alarmed by how much was being emitted by my old cellphone, so I changed that immediately!  A very useful device and reasonably priced! - Susan G.

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Note: This product was discontinued on April 1st, 2013.