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A nuclear magnetic resonance (NMR) spectroscopy machine is a laboratory installation, not a single box: a superconducting magnet, a console that generates and receives radio-frequency (RF) signals, a probe that holds the sample, and a computer workstation that runs the experiment. Its job is to give a chemist a spectrum from which chemical shifts, integration, splitting patterns and coupling constants can be read. This page describes the instrument and its safe use. It is a laboratory analytical instrument, not a patient scanner; for the clinical device see what an MRI scanner is. This page describes products and general use; it is not medical advice.
Who uses it: synthetic and analytical chemists, core-facility staff, teaching-lab students and instrument buyers who need to understand what they are specifying or booking.
What is nuclear magnetic resonance spectroscopy?
Nuclear magnetic resonance spectroscopy is an analytical technique. Bruker, a major manufacturer, describes NMR as allowing the direct observation of chemical reactions and as a primary quantitative method that can determine the concentration of molecules (Bruker NMR product overview). The goal of a routine teaching-lab experiment is stated plainly in MIT OpenCourseWare’s 5.301 NMR Operation Guide: obtain a well-shimmed NMR spectrum to determine chemical shifts, integration (for 1H only), splitting patterns and coupling constants.
For the wider family of instrument-based methods, see what analytical chemistry is, and for a different technique often paired with NMR, what a mass spectrometer is.
How does an NMR spectrometer work?
At the instrument level, the MIT guide breaks the system into three parts: a computer workstation, an NMR console that “generates and receives RF”, and the NMR magnet. The sample sits in a probe inside the magnet, and the console communicates with it.
The measurement workflow
In the MIT teaching-lab guide the sequence is: insert the sample, spin it, lock, shim, then run the proton experiment. Each step has a reason:
- Spinning: the spinner rotates the tube along the vertical axis within the magnet, creating a more homogeneous magnetic field.
- Locking: the deuterated solvent serves as an internal reference (the lock) that lets the spectrometer correct for magnetic field drift.
- Shimming: the objective is a well-shimmed spectrum, so the field is adjusted until the result is good enough to read shifts, splitting and coupling.
Deuterated solvent has a second job: it prevents large solvent 1H signals. That is why NMR samples are dissolved in deuterated solvents rather than ordinary ones.
Types of NMR systems
Bruker’s overview groups its systems into the classes below.
| System class | What the manufacturer says |
|---|---|
| High-field and ultra-high-field | GHz Class magnets are described as actively refrigerated and actively shielded (Bruker). |
| Compact | The AVANCE NEO NanoBay is described as having a small footprint for routine labs (Bruker). |
| Benchtop | Listed as its own class, with the Fourier 80 named as the example (Bruker). |
| Solid-state NMR | Listed as its own class (Bruker). A university core facility lists 3.2 mm zirconia sample tubes with a 49 μL sample volume (University at Albany). |
| MR microscopy and diffusion | Listed as a separate system family (Bruker). |
Hardware is also sold by component: magnets, consoles (AVANCE NEO), probes (room-temperature liquids probes and CryoProbes), automation and NMR consumables.
Specifications that matter: a real core-facility example
The University at Albany’s NMR facility page gives one concrete, fully specified instrument. It is a useful worked example of what a spec sheet contains.
| Item | Value (University at Albany) |
|---|---|
| Magnet | Superconducting, 600 MHz, 14.09 tesla |
| Probes | 5 mm high-sensitivity probe; 10 mm broadband low-frequency probe |
| Amplifier ranges | 550-610 MHz (high band); 5-245 MHz (low band) |
| Cryogen monitoring | Level meter for helium and nitrogen |
| Software | 1D, 2D and 3D acquisition |
| Solid-state accessories | 3.2 mm zirconia sample tubes, 49 μL |
The sample side is smaller. The MIT guide’s practice is a clean, dry 5 mm NMR tube free of cracks and chips, with 20-100 mg of compound dissolved in 0.7 mL of deuterated solvent, filtered if cloudy, then capped and labelled. The cryogen line in the table is one reason helium supply matters to NMR labs; see the helium shortage guide.
Safe use and handling basics
The MIT guide’s safety rules are the clearest short statement of magnet safety:
- NMR superconducting magnets are always on.
- People with pacemakers, cochlear and other medical implants should not enter the NMR room without a doctor’s permission.
- Keep all metal objects and electronic and magnetic devices, such as cell phones, keys and chairs, at least 5 feet from the magnet.
- If a tube breaks inside the magnet, contact lab staff immediately rather than attempting a fix.
Common mistakes
- Using a cracked or chipped tube. The guide requires a tube free of cracks and chips; a broken tube inside the magnet is a staff-level incident.
- Skipping the depth gauge. It prevents the tube hitting the bottom of the probe and centres the sample in the detection region.
- Inserting before the eject air is on. The guide says to wait until it is on before inserting the sample.
- Treating the magnet as switched off. It is always on, so the 5-foot rule applies at all times.
FAQ
What is nuclear magnetic resonance spectroscopy?
It is an analytical technique that lets chemists observe reactions directly and determine the concentration of molecules, and that yields chemical shifts, integration, splitting patterns and coupling constants from a spectrum.
How does nuclear magnetic resonance spectroscopy work?
A sample in a deuterated solvent is placed in a probe inside a superconducting magnet. A console generates and receives RF signals, and the operator spins, locks and shims before running the experiment. The deuterated solvent provides the lock that corrects for field drift.
What is magnetic resonance spectroscopy?
The instrument this page covers is the laboratory NMR spectrometer used for chemical analysis. The clinical scanner is a different device, covered in what an MRI scanner is.
Sources
- MIT OpenCourseWare 5.301, NMR Operation Guide (Kennedy and Gorham, 2010), https://ocw.mit.edu/courses/5-301-chemistry-laboratory-techniques-january-iap-2012/ae344c9fd47363ab76174b790375bde8_MIT5_301IAP12_NMR_Op_Guide.pdf, checked 2026-10-29.
- Bruker, NMR product overview, https://www.bruker.com/en/products-and-solutions/mr/nmr.html, checked 2026-10-29.
- University at Albany, NMR Spectroscopy facility, https://www.albany.edu/cfg/nmr-spectroscopy, checked 2026-10-29.
