GM330, 3D- Gaussmeter for DC, AC and Peak Hold Magnetic Field Measurements, 0.1G - 30kG
GM300 - laboratory gaussmeter family that reads AC/DC magnetic fields, true peak field, and total field magnitude, with a configurable alarm and onboard SD-card data logging. Accepts both single-axis and true 3-axis probes, with a range of 0.1 to 30,000 gauss.
Every GM330 includes:
- Your selected probe (single-axis or 3-axis), additional probes can be purchased on our homepage.
- Hard carry case
- USB-C charger/cable (power + data)
- Analog output cable
- Benchtop kickstand cradle
- NIST-traceable calibration certificate
- CE marking
Features:
-
Displays 3 axes and magnitude - every axis plus the calculated magnitude update together; no rotation or orientation guesswork.
-
High dynamic range - resolves a small variation inside a large DC or AC field.
-
Programmable alarm - audio and visual alarm indication of field exceeding threshold
-
Onboard SD-card data logging - record directly to the meter; download data over USB with AlphaApp3.
-
High-speed AC capture - streams fast-changing fields and waveforms.
-
Intuitive to use - begin measuring at power up, no setup or calibration required, retains last settings.
-
Interchangeable, auto-detected probes - 3-axis and single-axis; ST probes to 30 kG.
-
Analog output - One output per axis, plug magnitude, single wire common.
-
Peak-hold monitoring - continuously displays the maximum field since the last reset, capturing brief spikes with polarity sign.
-
Zero / tare with a button press.
-
NIST traceable, yearly calibration service available
Product Description
Model GM330 is designed to measure strong and moderate magnetic fields, such as from magnets, solenoids, and electromagnets. As the laboratory-class successor to the popular GM-2, it’s fast and intuitive to use, with an extremely high dynamic range - measuring from 0.0 to 19,999.9 gauss in 0.1 gauss steps, then automatically switching above 20,000 gauss to read 20.000 to 29.999 kilogauss in 1 gauss steps. A change as small as 0.1 gauss can be resolved even within a 14,000 gauss field - typical of the strongest permanent magnets. It reads DC field, AC field, and peak field, with a fast peak-hold that captures brief positive or negative transients most meters miss. A configurable alarm can sound when the field exceeds a threshold, drops below one, or falls inside or outside a range you set - and on a 3-axis probe, each axis can carry its own independent alarm profile, useful for a mounted probe in an asymmetric field.
Where the GM330 pulls decisively ahead is measurement and data. It accepts both single axis and true 3-axis probes - three sensors reading the X, Y, and Z field components at once, with each axis and the calculated total magnitude updated to the screen simultaneously. Position the probe anywhere in the field and read the full vector and true magnitude, with no rotation and no hunting for the right orientation. Its data recording and streaming are far more capable as well, with onboard SD-card logging and high-speed AC capture for following fast-changing fields and waveforms the GM2 couldn’t track. For R&D and QC work that depends on recording what a field is actually doing over time, this is the upgrade that matters.
The meter is shipped ready-to-use and includes one probe of your choice, a USB-C cable for data logging and power, analog output, and a NIST-traceable calibration certificate. It runs from its internal power or USB, so it can be left permanently on when needed.
A full range of interchangeable probes is available in 3-axis and single-axis variants, with multiple tip shapes - flexible/universal, axial, and transverse - so the GM330 adapts to everything from strong permanent magnets to fine, low-field work. The meter automatically detects the installed probe. Single-axis probes remain the right choice when you already know the field’s direction and need only one component: a single sensor fits into a thinner, smaller tip that reaches into narrow gaps and bores a three-sensor head can’t, and it’s the more economical option for routine one-axis work. Single-axis ST probes cover 0.1 gauss resolution up to a 30 kilogauss maximum range.
There are four interchangeable probes available, each at a range of 0.1G - 30kG:
-
ST 3-axis, Vector measurements, can also be used to scan objects for residual magnetism
-
ST flex (universal), most popular probe, as it can be used in a variety of measurement applications
-
ST thin transverse, thin (0.65mm) rigid probe for transverse measurements with distance gauge
-
ST axial, probe purpose built for axial measurements in coils, bores, solenoids, ect.
Choice of one of these probes is included with the meter. Please specify when ordering.
Output: The GM330 provides an analog voltage output proportional to the instantaneous field—one output per axis on a 3-axis probe as well as a generated Magnitude. Output is the true field waveform (it stays live even when the display is switched to AC or Peak Hold), suitable for a multimeter, oscilloscope, or ADC.
Applications:
- Rapidly scan a part to check magnetization; the alarm sounds only where the field matches the profile you set, so it can be swept quickly to flag residual magnetism or out-of-spec magnets.
- Measure background field (including Earth’s) direction and strength, both DC and AC.
- Log or stream field data over time for experimental setups, using SD-card recording or USB streaming to AlphaApp3.
Technical data:
| Measurement parameter: |
DC & AC magnetic flux density |
|
DC Range/Resolution (ST Probe):
|
±19,999.9G /0.1G; 20kG-30kG /1G indicates polarity |
| AC Range/Resolution (ST Probe): |
1500.0G / 0.1G |
| Accuracy with probe, 16° to 29°C: |
1% of DC reading / 3% AC ±10 Counts / 1% peak hold |
| AC Frequency Range: |
10-2000 Hz |
| Peak Hold Speed: |
2 millisec pulse is 71%, 5+ millisec pulse is 100% ±1% |
| Output Type: |
Analog DC Signal, USB |
| Output Magnitude (ST Probe): |
Below 20kG, output is 0.1mV/G. Above 20kG, it is 0.01 mV/G |
| Meter Size: |
138 x 91 x 41mm³ |
| Weight: |
213g |
| Battery: |
Internal LiPo, USB recharge |
