Building a budget EMF detector - component guide and testing results

I've been frustrated with the cost of commercial EMF detectors (£150-400 for decent ones) so I've built my own using a simple Arduino circuit, an MCP3008 ADC converter, and a standard coil antenna. Total cost: £32 including the housing. Took me about eight hours to assemble and calibrate.

I've tested it against a commercial Trifield meter in my flat and it gives comparable readings within 5% variance on the 50Hz domestic mains frequencies. The trick is getting the antenna wound correctly - I used 200 turns of 0.5mm copper wire on a 50mm PVC former.

Happy to share the Arduino code and circuit diagram if anyone's interested in building one. The main limitation is it's single-frequency focused rather than broadband, but for investigating UK domestic properties it's absolutely adequate. Has anyone else built custom paranormal investigation equipment?

This is brilliant work. I've been wanting to build something similar but didn't have the technical background. Would definitely appreciate the code and diagram. One question though - how did you handle the signal conditioning? Raw sensor output tends to be very noisy.

Total cost: £32

Have you tested it near high-voltage sources? The real test is whether it can distinguish between mains interference and genuine anomalous electromagnetic activity. That's where commercial detectors supposedly differ from DIY solutions.

Post the circuit diagram on the forum - I want to build this. I'm currently using my old mobile phone with an EMF detection app, which is basically useless, so this would be an upgrade. How accurate is the calibration process?

The Arduino approach is solid. I'd recommend adding a data logging function so you can record readings over time rather than just in-the-moment measurements. That'd give you real temporal patterns for hauntings.