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# How To Build A Gauss Meter

Radio Shack sells a calibrated Hall device as P/N RSU 12033684, for about. . (This is saying that its sensitivity.121mV/G)  Its non-linearity is only.2 and its symmetry is about.8! . It uses a linear Hall effect device and some op-amps and resistors and things from Radio Shack. If the output were connected to a scope, you would also be able to see the varying magnetic field of an AC electromagnet!

, not critical. The closest proximity to the electromagnetic source does not necessarily give the highest reading, probably because the induced currents in the body remain localised at close proximity.

## How to make the simplest magnetometer(or Gauss meter)

C1 and C2 values are not critical, I ended up using a 22uF for C1 and.47uF for C2, whatever I could find in the junk box.

Arduino Uno and a tiny oled screen into something that displays the magnetic, or Gauss level.

Rick Hoadley hosts a site called Magnet Man. How much the voltage rises or falls is dependant on the gauss measured. Using a hall sensor, the meter can measure the Gauss/Flux density and polarity of a magnet. Though full documentation isnt available right now, Garofalo says that hell make it available once he repackages everything in a smaller format with an enclosure. The circuit uses a 9v batter for power, and a push button switch to power it up, so I cant forget to turn it off.

### Build your own Gaussmeter - Blue GuitarHow to Build Your Own Gauss Meter for Measuring the Strength

More details on my Blogger: /201. R1 was chosen through trial and error, and VR1 is used to set the meter to mid scale when no magnet is present, in effect zero'ing the meter. The circuit is simple to replicate with a Linear Ratiometric Hall Effect Sensor, the SS495A from Honeywell (2.50Euro). Whats really neat is that the Gauss meter can only be turned on and off by placing a magnet on the center of its faceplate.

Many of the meters from stereo's are not the best quality and usually not very linear, so I've added a couple of test points where I can attach the test leads of my digital multimeter, for when I need to make a more accurate Gauss. It also shows whether its observing the north or south pole of the magnet, which certainly could be useful in some situations. Digital Radar Speedometer, capacitance Meter, digital Remote Thermometer, field-strength meter.

Jeffrey Holland

U1-5 means U1 pin 5).

Joe Howlett

The output of the inverting op amp, U1 pin 8, is connected to a 1K resistor to the inverting input of U1 pin. . While the movement may seen to be a disadvantage, if you have a bench-top instrument with a probe, there are times when you'd want to put the probe into this gap, or that gap, employing the very movement you would need to make the measurement. Datel, their triple output model, which can supply.00Vdc at 500mA, 15Vdc at 200mA and -15Vdc at 200mA, all with 120Vac. .

Jeffrey Holland

The key to the Gaussmeter is the magnetic field sensor, labeled HE3503 in the schematic above. . If you knew the field direction, then using a sensor off axis would result in a smaller on axis (measured) component.