# Dirty-electricity (line harmonics) meter

> Plugs into a socket and reports high-frequency harmonic content riding on the mains, the quantity used to judge dimmers, LED drivers, inverters and switch-mode supplies.

- Canonical URL: https://emfbase.com/meters/dirty-electricity-meter
- Collection: Instruments
- Record id: `meters:dirty-electricity-meter`
- Status: verified
- Last verified: 2026-08-12
- JSON: https://emfbase.com/api/meters/dirty-electricity-meter
- Also known as: Graham-Stetzer meter, line noise meter, microsurge meter

## Key values

- **Band covered:** conducted harmonics, roughly 2 kHz – 1 MHz
- **Quantities measured:** electric field strength
- **Typical price:** $80–$400

## Detects

- Harmonic content injected by phase-cutting dimmers and cheap switch-mode supplies
- Relative before/after effect of removing a suspected device
- Power-line-communication carriers used by some solar optimisers and smart appliances

## Cannot detect

- Radiated fields — this is a conducted measurement at the socket
- Which device is responsible, without switching devices off one at a time
- Anything expressible in a recognised SI exposure unit: the common 'GS units' scale is proprietary and not an exposure metric

## What to insist on

- A stated frequency window rather than an arbitrary index
- Readout that can be compared over time and between circuits
- Ideally an oscilloscope line adapter for anyone who needs the actual waveform

## Related records

- [Dimmer switch and phase-cutting controls](https://emfbase.com/emitters/dimmer-switch): Phase-cutting dimmers chop the mains waveform and inject harmonics from a few kilohertz up to about 1 MHz onto the building wiring — the classic source of what practitioners call dirty electricity.
- [LED lamps and low-cost drivers](https://emfbase.com/emitters/led-lighting): The switch-mode driver inside a cheap LED lamp can put measurable high-frequency harmonics on the circuit and produce visible flicker; well-filtered drivers do neither.

## Sources

- `sbm-2024` Institut für Baubiologie + Nachhaltigkeit (IBN) (2024). *Building Biology Evaluation Guidelines for Sleeping Areas (SBM-2024)*. https://buildingbiology.com/site/downloads/SBM-2024_EVALUATION_GUIDELINES_EN.pdf — ngo, link checked 2026-08-12

Data licence: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Dataset version 2026.08.1. Retrieved from EMFBase, https://emfbase.com.

This record is reference data, not medical or legal advice. Regulatory limits, scientific guidelines and precautionary values are labelled separately and answer different questions.